The monthly fee may have included call outs, believe me, a ringing siren at 3 am is worth the money. Try getting someone out to have a look and you would need to pay a call out fee so the anual fee soon looks good value, all imo of course.
How long has it been installed?
But if they give you their unique engineers code then they compromise every system with the same code...
Give BMW a call and ask for the code for the 2017 map updates
I know a couple of ex ADT, now ROMEC guys, all happy and they seem a decent company to work for, my understanding was they didn't lose the contract, they chose to scale right back.