Telkom account issues.

I have a 20 gig Teikom contract for R499.00 and a spend limit of R10.00 put in place in September when they overcharged me to the tune of R976.95. Just got off the phone with Tamara Nune(sounds like), who tells me i have a spend limit of R500.00 - spent like 15 minutes giving my name, address, ID number, bank and when debit order goes through - only for her to tell me that she has to escalate and can't assist. Can anyone advise how to bring Telkom to account, I have a strong impression that Telkom are robbing me.