MTN exceeded my credit limit by R5000.00

In December I bought a 3GB Internet voucher and by the 9th of Jan this was used up. Unknowingly I continued using internet and received a SMS the 15th of Jan that my credit limit of R1617 was reached and that my account will be blocked. It got blocked and I went to the Stellenbosch branch on the 20th Jan. In the branch they checked my account informed me it was only R500 in credit. This was also confirmed by one of the support consultants from the call centre ( when you call 808 ) . <br> <br> I requested the call centre agent to load an additional 3GB bundle (get an extra 3GB) , and to unlock my account.<br> This 3GB bundle have not been used up yet, and valid till 20 March.<br> <br> Today, I received a SMS from my bank that MTN have debited my account with R6881.73<br> <br> The call centre agents is saying that their credit limit is not reliable and that somehow I used R5000.00 over my credit limit on internet because their system is \behind"and unreliable<br> <br> They are charging me now R6000.00 for 3GB while it only costs R300 if you buy a bundle"