Why are they even operating as a financial service provder if they cannot kee straight records

MBD chase me for an MTN account I Ihad cancelled, eventually I capitulated and pd over six months, received a call to make an extra payment in the fifth month to quallify for discount, which I did, Still awaiting my confimation letter of payment after many requests and confirmation of email address and yet stll are hounded by MDB to make payemnt even after sending proof of payment five times.