Cannot provide service - but expect to be paid

Telkom is trying to charge me for a service they could not provide when I moved from Fourways to Bryanston. They took my notice of change of address and said i would get it installed in 1 - 2 weeks. After many follow-ups i was told that this address is now serviced by Fuma and not by them. So basically they cancelled my service and could not provide the product but are expecting to get paid for 3 months of no service. I now have Telkom's debt collectors who i have sent info too about the consumer protection act. They are just ignoring me. Now they are threatening me further. I dont know what else to do as one cannot complain to Telkom direct.