Used correct HTTP error

app/services/cart_service.py

@@ -62,7 +62,7 @@ class CartService:
 				return {"Success": "Successfully added to cart"}, 200
 
 		except Error as e:
-			return {"Failed": f"Failed to update item count in cart. Reason: {e}"}, 400
+			return {"Failed": f"Failed to update item count in cart. Reason: {e}"}, 500
 
 	@staticmethod
 	def delete_from_cart(user_id: str, product_id: int) -> Tuple[Union[dict, str], int]:
@@ -85,7 +85,7 @@ class CartService:
 
 				return {"Success": "Successfully removed item from cart"}, 200
 		except Error as e:
-			return {"Failed": f"Failed to remove item from cart. Reason: {e}"}, 400
+			return {"Failed": f"Failed to remove item from cart. Reason: {e}"}, 500
 
 
 	@staticmethod
@@ -119,7 +119,7 @@ class CartService:
 			return results, 200
 
 		except Error as e:
-			return {"Failed": f"Failed to load cart. Reason: {e}"}, 400
+			return {"Failed": f"Failed to load cart. Reason: {e}"}, 500
 
 
 	@staticmethod
@@ -176,7 +176,7 @@ class CartService:
 
 		# clear cart
 		except Error as e:
-			return {"Failed": f"Failed to load cart. Reason: {e}"}, 400
+			return {"Failed": f"Failed to load cart. Reason: {e}"}, 500
 
 		return {"Success": "Successfully purchased"}, 200