Airties contract - will charge you forever

Airties cost R 1300 each to buy to you own, we have been renting ours Airties (3x in total for 2 years) as part of our Vox fibre contract - just called Vox to ask till when do we pay for the hardware on our contract as it has been 24 months, Vox response indefinitely. Please read the terms and do not make the same mistake.