Telkom taking my money without my concerns!!!

Telkom did not debit end of the month. Debit order normally goes off month end but last month February the debit order did not go off... and I had all the funds on my accounts as I was prepared..Reason I don't know why??!! How ever i had to pay the amount telkom didn't debit at shoprite for the February month on the 3rd of march.. But telkom debited today twice the normal. This is not is not suppose to be happening. No one is getting back to me?!!! Why did telkom debit now but i paid my installment at shoprite?? And why did it debit today?