PLAYSTER.COM cancelled my subscription without giving me a valid reason Internet

I signed up for Playster because it provided unlimited audiobooks at a decent price. I used it on various electronics, an ipad, a computer and a samsung phone, I used it plenty since I spend a lot of time driving to my various offices and out of state to settle my son in college. I also listen to it on my computer while I do my computer work for my job. Well anyway Playster kicked me out without giving me a specific reason. They sent me a list of possible reasons insinuating that I am doing something illegal. I tried to appeal and they rejected my appeal without giving me a reason. As far as I know I was doing nothing illegal. I also was told by a customer service at Playster that I can use it on as many electronics as I want. I was the sole user on my account at Playster I think the real reason I got kicked out is that I may have been costing them to much money. So really it is not an unlimited program. If you use it a lot you get kicked out.  It also irks me that the company did not talk to me before denying my appeal.