why can't I return Apple TV

I have internet with Spectrum. Since they send me at least two letters per week to get cable I finally said ok. I pay $69 for internet only so wanted basic cable for $44 plus $44 for the internet. I just wanted to watch tv with a few more channels than I get with my antenna. The Spectrum guy said the Apple TV would be perfect for me. I said ok. But this is not basic cable. It is a streaming service, which i do not want since I already have Netflix. Today I waited over an hour at the Clairemont Spectrum only to be told I could only return the modem, but not the Apple TV and that I would have to take it to UPS. I came home to call to make sure i had the right return label and was told i could not return the Apple Tv and that I would be charged $187, (it is only $149 at Best Buy). I have been a Time Warner/Spectrum customer for a long time and just took the product back to the store when my needs changed. But this time they won't take back the product I got from them, that does not provide what I asked for. How is this even legal? I do not want the Apple TV and I do not want to get stuck paying $187 for it. Any suggestions?