Business Software Solutions Sold me a useless pos system for my restaurant Layton Utah

i bought a pos system from them which was posted on ebay, 1 dell optiplex used,2 epson printers used,cash drawer.monitor and software which i paid $1,155.00,i was never explain that they were going to charge me $30.00 monthly royalty fee for using their software,what it was explain to me they were goning to charge $30.00 monthly for support,i never need em so i was good not paying them for any support(which is that if you have any questions and if you call them they can charge you,that it is the way evberybody works).But this people on their software after 3 months they put a lock so you can't used the system on a saturday so they can charge you their out of hours fee $4.00/min(they work form monday-friday very convenient).I call them on saturday cause i need the keys for the sotware and they told me i have tp pay $90.00 plus after hours fee.
So imagine my suprise i have to paid them for support i don't need and they change saying it was for using their software,i call on monday and i ask for supervisor they were extremely rude on the defensive side,she was yelling at me threating me if i went public they have lawyers so they can sue me.
So is like if i buy a computer but because i used their software they charge me a monthly fee every single month for ever(is this a scam or what).So i turn out payting for a computer system mostly used which i cannot used because the software is locked.

Tarpest
brownsville, Texas
U.S.A.