MBD Credit solutions/Standard bank

some time ago i had cheque account with standard bank i stopped using the card i didnt go to Standard and close the card cause i didn’t know i will owe them if i stopped using the card now they handed over my account to MBD Credit Solutions...now the problem is i made arrangements to pay the account by the end of the month but they deducted the money on the 25th and i reversed the money cause that money is for the transport now today i got a call from a rude consultant she say its up to me to pay the account or standard bank will take legal actions against me i don’t like the way this consultant is speaking to me!!!