Internet

I had AT&T internet installed the other day after a cancelled Spectrum. So I unplugged Spectrums equipment (Sagecom, Arris) to return it to the store. After unplugging this equipment I went to watch TV and I just had the word ROKU all over the screen and could not pull up any channels. I need a technician to come look at this for me. Your recording doesn't have a situation like this and your representatives just tell me another number to call. So now I have 3 devices plugged to my TV. Could you send a technician please.