Breaching of Contract.

So, I had internet LTE with WebAfrica, and when I contacted them for the agreement I asked them why do I get a free modem... they advised that if I cancel they come and collect the modem. So after a couple of months with them I canceled with them... waiting for them to phone me to come and collect the Modem... So did not receive a phone call for collection... just a R1999 deduction from my account. Not doing what is on the agreement.