Telkom overbilled!

I've had a Telkom 8ta data card for 4 years on contract at R199 per month. It comes to an end in mid Jan so I gave notice in Dec to cancel and app**** for Telkom ADSL line to be installed. On 25 Dec, Telkom suddenly debited our bank account with R299 with no invoice, no communication as to why. I went into the Telkom branch at 09h00 yesterday (28 Dec) to query. A query was \logged"and I was told that Telkom guarantee to call me within two hours. By 15h00 I still had heard nothing"