Honeywell design the architecture, the programming is ADT.
There is an argument that if you'd planned better you could have had the work done or even down powered on your last inspection visit.
There is an argument that the programming remains intellectual property of the installing company.
You own the equipment only, and most companies will charge for attendance, this will be more expensive outside of contract as you have now found.
Nothing like your car analogy BTW.
Lol, used to like my trips to ARCO when I worked in t'Hull.
Guy in the office used to kick the arse out of the sex chat lines and put it on his card as ARCO, his Mrs worked for HSBC and rumbled him eventually.