Standard Bank's Worst Service

Very disappointed with standard bank's service, just recently app**** for vehicle finance with them then everything went smoothly and it was approved and October i was supposed to make my first payment and they did not debit. However I've made several attempts like calls, emails even went to Facebook sent them an inbox so that they could collect their money then nothing happened. The second month they managed to collect on date then last week received a call saying I am in arrears and it will affect my credit score really badly, why didn't i make my first installment even though I made several attempts for them to debit and they transferred me to collections department so that i can make an arrangement, which we did then they promised to send me banking details to use to make a transfer because they can't debit double amount for October and Dec and to this day still waiting for banking details.