English Conversation Practice - Negotiating Delivery Fee

Customer: How much is the delivery charge?
Sales clerk: 5% of the total order amount.
Customer: That's expensive. We're buying a large amount of office supplies. Can you give us a discount on the delivery fee?
Sales clerk: Let me talk to my manager.
Customer: If we are happy with the service, we will continue buying all of our supplies from your company.

1. How much is the delivery charge?
5% of the total order amount
One-time $5 charge
$5 per order
Free delivery

2. What is the customer buying?
Clothes
Appliances
Computers
Office supplies

3. What does the customer ask the sales clerk?
Discount on delivery fee
Refund policy
Bulk orders
Business hours