TELKOM - UNPAID MAGTAPE, AGAIN???

I received a text message from FNB today advising that my payment of R361.25 was UNPAID on 20 May. IMPOSSIBLE as I had a CREDIT balance of R563.20 on 19 May. I spoke to 2 ladies at Telkom who CONFIRMED that they had received my payment. However, my account has now been CREDITED with R361.25 which means that Telkom is sitting with a DEBIT?? This is the SECOND time I have experienced this problem through NO fault of mine. In February my payment was also UNPAID and Telkom charged me R202.70 iro. PAYMENT REJECTION FEE. Please get this issue resolved.