Telkom deducts R1300 from account but is blocking phone for non payment, and not calling when we request a call back.

For the third time since the contract started, Telkom is deducting money from my son's account for his mobile contract, all the while they are blocking his phone, again this month, they deducted R1300 while his contract is R800, blocked his phone for non payment, and he has logged 2 disputes the past 2 days, requesting a call back, but get no response. The previous 2 time he has had to get an affidavit and submit is, because the previous 2 times Telkom realised that there ********** activities, he had to lay a claim of ***** before the matter was resolved. IS IT AGAIN FRUAD? Telkom deducted R1300 but is not applying it to his account, **********ly. How can we get TELKOM to phone him and SORT IT OUT? My son's number is ***