Telkom billing department ***********

I setup a debit order with telkom for my mobile account to be debitted on the 25 of the month. They did not debit and may and double debited today on 15th of June at such a bad time in the month how hard can it be to debit on the allocated day or is this just the business model at telkom to debit when people may not have enough so that you can fine them for insufficient funds. I am cancelling this mobile contract as this has happened more than once and i have had it. On a side note they could not even enter my name correctly for said account even with my id in front of them and me pointing it out totally useless and ***********