We're so sorry for our delayed response, and for the picture issues you've been having with your TV service.
I appreciate this may have been one of the first things you tried, but did you try using a different HDMi port on your TV? Have you also ensured that there isn't an issue with the TV itself, and that the problem only occurs when viewing the source that your TV box is connected to?
If you have tried all these things, you'll likely need a replacement box sending out to you, if you haven't been able to sort one already. Give me a shout if you still need help and we'll go from there.