Telkom reap off!

After paying off and closing my two contracts with Telkom, I started getting un authorized debit orders of R20 from them, I reversed R40 because they were not authorized to debit... I called and enquired as to why were they still debit as the contract had reached term and closed... They told me the R20 was for having the simcard(which ddnt get any data or airtym)... Now because I had reversed R40 back into my account I'm now owing Telkom R1360. 65...what kind of reap off is this!?? M getting calls from their lawyers, saying my account was handed over... I feel betrayed for being a loyal customer for such a long tym... Now R40 has tuned into over a 1000 rand that I need to payoff by force... ??