70% price increase after only a few months when i moved my unit from one car to another.

I installed 3 units Beame for R59 a few months ago. I asked the installer and the marketer if i can move the unit from one vehiclke to anather, he confirmd it is no problem thy will install a new one in the new vehicle and i will just go on with my monthly fee till the contract end. I informed them that i want one unit to be moved to a new vehicle. thy said no problem but the fee will now be R99 per month. i said but i am currently paying R59 and the person said prices went up. but this is wrong i am paying R59 as per my contract and now thy want to force a R99 premium on me. Please dont use this service if you move your unit from one car to anather thy increase your account within only a few months with 70% if thy do this every year you will be paying for this unit a few hundred rand.