diff --git a/src/common/enums/message.enum.ts b/src/common/enums/message.enum.ts
index f7e5325..0f78b5d 100755
--- a/src/common/enums/message.enum.ts
+++ b/src/common/enums/message.enum.ts
@@ -714,6 +714,7 @@ export const enum CartMessage {
   DELIVERY_METHOD_NOT_FOUND = 'روش ارسال یافت نشد',
   DELIVERY_METHOD_NOT_ENABLED = 'روش ارسال برای این فروشگاه فعال نیست',
   PAYMENT_METHOD_NOT_FOUND = 'روش پرداخت یافت نشد',
+  PAYMENT_METHOD_NOT_BELONGS_TO_SHOP = 'روش پرداخت به این فروشگاه تعلق ندارد',
   PAYMENT_METHOD_NOT_ENABLED = 'روش پرداخت برای این رستوران فعال نیست',
   WALLET_NOT_FOUND = 'کیف پول کاربر یافت نشد',
   WALLET_INSUFFICIENT = 'موجودی کیف پول کافی نیست',
diff --git a/src/modules/cart/providers/cart-item.service.ts b/src/modules/cart/providers/cart-item.service.ts
index 636a59a..e976719 100644
--- a/src/modules/cart/providers/cart-item.service.ts
+++ b/src/modules/cart/providers/cart-item.service.ts
@@ -51,8 +51,8 @@ export class CartItemService {
   /**
    * Get item index in cart
    */
-  getItemIndex(cart: Cart, shopId: string): number {
-    return cart.items.findIndex(item => item.productId === shopId);
+  getItemIndex(cart: Cart, productId: string): number {
+    return cart.items.findIndex(item => item.productId === productId);
   }
 
   /**
@@ -77,8 +77,8 @@ export class CartItemService {
   /**
    * Remove item from cart
    */
-  removeItemOrFail(cart: Cart, shopId: string): void {
-    const itemIndex = this.getItemIndex(cart, shopId);
+  removeItemOrFail(cart: Cart, productId: string): void {
+    const itemIndex = this.getItemIndex(cart, productId);
     if (itemIndex < 0) {
       throw new NotFoundException(CartMessage.ITEM_NOT_FOUND);
     }
@@ -88,8 +88,8 @@ export class CartItemService {
   /**
    * Decrement item quantity or remove if quantity reaches 0
    */
-  async decrementOrRemoveItem(cart: Cart, shopId: string): Promise<void> {
-    const itemIndex = this.getItemIndex(cart, shopId);
+  async decrementOrRemoveItem(cart: Cart, productId: string): Promise<void> {
+    const itemIndex = this.getItemIndex(cart, productId);
     if (itemIndex < 0) {
       throw new NotFoundException(CartMessage.ITEM_NOT_FOUND);
     }
@@ -102,7 +102,7 @@ export class CartItemService {
       return;
     }
 
-    const product = await this.productService.findOrFail(shopId);
+    const product = await this.productService.findOrFail(productId);
     cart.items[itemIndex] = this.buildCartItemFromFood(product, newQuantity, existingItem);
   }
 }
diff --git a/src/modules/cart/providers/cart-validation.service.ts b/src/modules/cart/providers/cart-validation.service.ts
index 651f0b8..6e79b66 100644
--- a/src/modules/cart/providers/cart-validation.service.ts
+++ b/src/modules/cart/providers/cart-validation.service.ts
@@ -1,4 +1,4 @@
-import { Injectable, NotFoundException, BadRequestException } from '@nestjs/common';
+import { Injectable, BadRequestException } from '@nestjs/common';
 import { EntityManager } from '@mikro-orm/postgresql';
 import { Product } from 'src/modules/products/entities/product.entity';
 import { UserAddress } from 'src/modules/users/entities/user-address.entity';
@@ -85,11 +85,6 @@ export class CartValidationService {
     }
   }
 
-  /**
-   * Get delivery method for shop or throw if not found
-   */
-
-
   /**
    * Get enabled delivery method or throw if not found or disabled
    */
@@ -126,7 +121,7 @@ export class CartValidationService {
   async getEnabledPaymentMethodOrFail(shopId: string, paymentMethodId: string): Promise<PaymentMethod> {
     const paymentMethod = await this.paymentMethodService.findOneOrFail(paymentMethodId)
     if (paymentMethod.shop.id !== shopId) {
-      throw new BadRequestException('CartMessage.PAYMENT_METHOD_NOT_BELONGS_TO_SHOP');
+      throw new BadRequestException(CartMessage.PAYMENT_METHOD_NOT_BELONGS_TO_SHOP);
     }
     if (!paymentMethod.enabled) {
       throw new BadRequestException(CartMessage.PAYMENT_METHOD_NOT_ENABLED);
diff --git a/src/modules/cart/providers/cart.service.ts b/src/modules/cart/providers/cart.service.ts
index abf6881..20ca664 100644
--- a/src/modules/cart/providers/cart.service.ts
+++ b/src/modules/cart/providers/cart.service.ts
@@ -89,7 +89,7 @@ export class CartService {
       paymentMethodId,
     );
 
-    // Recalculate totals first so wallet check uses up-to-date total (delivery method may have changed above).
+    // Recalculate totals first so wallet check uses up-to-date total (delivery method/address may have changed above).
     await this.calculationService.recalculateCartTotals(cart);
 
     if (paymentMethod.method === PaymentMethodEnum.Wallet) {
@@ -103,8 +103,8 @@ export class CartService {
       cart.description = description;
     }
 
-    // Final recalculation + save and return cart
-    return this.recalculateAndSaveCart(cart);
+    // Save and return cart (totals already recalculated above)
+    return this.saveTouchedCart(cart);
   }
 
   /**
@@ -290,7 +290,7 @@ export class CartService {
       fullName: `${address.user.firstName || ''} ${address.user.lastName || ''}`.trim(),
       phone: address.user.phone,
     };
-    return this.saveTouchedCart(cart);
+    return this.recalculateAndSaveCart(cart);
   }
 
   /**
@@ -307,6 +307,10 @@ export class CartService {
       shopId,
       paymentMethodId,
     );
+
+    // Recalculate totals first so wallet check uses up-to-date total
+    await this.calculationService.recalculateCartTotals(cart);
+
     if (paymentMethod.method === PaymentMethodEnum.Wallet) {
       await this.validationService.assertWalletHasEnoughBalance(userId, shopId, cart.total);
     }