Why doesn't my Cinemax On Demand not work! - DirecTV

I have spent hours on the phone with "customer support" since I switched from Uverse to Direct TV. I get the Cinemax channels but not Cinemax on demand. I was told by first call that they were not sure why and maybe I had no internet. I had internet. Then I was transferred to "support" After being on the phone for 1 hour 22 mins. her answer that she checked and other people also having problems but she could not tell me when it would be corrected! I asked AT&T has no time frames, hours, weeks, months. Answer No. Her solution: well you can still get Showtime & HBO on demand. I asked to be transferred to the department that cancels service. I was so frustrated by this time that I wanted to cancel my 3 cells, internet and Direct TV. Customer Service apologized stating that the answer I was given was unacceptable. She then came back on the line and told me it would be corrected withing a few hours. That was 3 days ago and ofcourse it still does not work. All the other on demands work but the one I want. Ready to dump ATT all together after over 10 years. Any suggestions since support doesn't have a clue or just doesn't care. Also, I was promised that when I switched from Uverse to DTV I would have all same channels. So far there are 3 channels that I always watch (DIY, GAC and some fishing channel my husband watched) that DTV does not have.

This question, "Why doesn't my Cinemax On Demand not work!," is about DirecTV channels, programming, equipment, and sports.