A regular client of 3 years typically orders prints from us quarterly came in over a week ago with an order. Sometimes this client comes in with the designs and sometimes we do the designs in house. When we were finished with the designs we sent the proof and then heard word from the client that they actually had the designs already produced so we used the designed provided. We had sent a bill to the client Monday in regards to the prints and design time we spent. Now the client feels that they shouldn't have to pay for the design time. So what to do?

1. Let it slide and remove the design charge?
2. Proceed with the request to be paid?