Fix small SD tv images or lose customers

This has been going on too long

even Xfinity big screen smart tvs in Xfinity showrooms are stretching SD HBO, Showtime, and other “Premium” 

channels. Please offer all channels in HD

or get adequate software engineers to remedy. I have had 3 technicians to my house to no avail. Have 5 tvs with HBO HD coming on 1 channel full screen the other  5 HBO channels are displaying at about 60% of screens. Please get up to speed with full screen displays or lose business.