Threaten with blacklist

I moved from George to Mosselbay few months before my contract expired and requested that my contract be cancelled but my request was rejected and the only option was to buy the contract out which I did and now after two years i get a sms from a attorney that state that they will blacklist me if i don't pay the outstanding amount, i was so shocked that i phoned them to hear what's going on and they advised me that the subscription was not cancelled, now who do you blame because this contract was paid up and cancelled in 2016 due to the fact that I can not use the service where I stay....... No Motion Fitness in Mosselbay. Can anyone help me with this matter please