Poor service from MTN

Please employ competent people in your billings department. My debit date is the last day of the month. So 30th November fell on Sunday. The next debit run will go off on Tuesday. This morning (Monday) I receive a threatening SMS stating that I will be disconnected if I do not settle payment immediately. Stop this bullying and don't stress us the pensioners. You guys are a joke. Hang your heads in shame. Bunch of clowns.