First let me say: This is a customer to customer help forum,with almost no oversight from Comcast. We are customers like you, with no access to Comcast files or records.
Most of the experts here dose try to help. Some are Comcast can do no wrong people.
Comcast like most big company's have very little interest in the customers opinions,or input. If you will post more about your problem,one of the experts here can kick your problem up the Comcast food chain. There is people here that will try to help you.
This is my uninformed answer. If you tell the installer or the window ckerk. The office people dont hear it and they are happy. No bad press, they think they are doing a good job. As for the 20 dollars. You have to sak for it. And some cases keep asking for it. 1-800-comcast and email. You can send an email to the We Can Help Comcast Team.