Improved parsing utility bills

MoneyMap/Services/OpenAIReceiptParser.cs

@@ -205,7 +205,15 @@ namespace MoneyMap.Services
   ]
 }
 
-Extract all line items you can see on the receipt. For each item, try to extract quantity, unit price, and line total. If any field is not clearly visible, set it to null. Respond ONLY with valid JSON, no other text."
+Extract all line items you can see on the receipt. For each item:
+- description: The item or service name
+- quantity: Only include if this is an actual countable product (like groceries). For services, fees, charges, or taxes, set to null.
+- unitPrice: Price per unit if quantity applies, otherwise null
+- lineTotal: The total amount for this line (required)
+
+For utility bills, service charges, fees, and taxes - these are NOT products with quantities, so set quantity and unitPrice to null.
+
+Respond ONLY with valid JSON, no other text."
                             },
                             new
                             {