Bad service

I am so terribly dissapointed. I missed paying my telkom account 2 months ago and paid my account the next month telkom literally changed my debit order date without even consulting with me. I received a invoice stating that i should pay R551 and then again R349 the R349 is the price i shhould pay every month instead of deducting on the end of the month telkom deducted the 15th and tried to deduct the whole amount of 900 which is unacceptable cause im supose to pay my monthly installment only the the end of the month...