Incorrect debit order date according to our agreement

The agreement was to debit on the last day of month for the credit card I took late last month. This time the debot went off on the 15 Jan and was unpaid, cost me unpaid fees and loweringy credit scoring. Worst part is the credit card is blocked due to 5 days overdue. According to our agreement the account is not supposed to be overdue. Then the callcentre drops calls on me, went to collections then collections gave the ********** , called and spoke to agent who transferred me to a quiet ivr channel. What a service, how can you help me, by fixing your mess please, its inconveniencing, no pne authorised you to debite mid-month.