DPP customer complain query not resolved yet

On the 11th April this month i logged a query about DPP promoting consultant not having called me back after the line cut while busy talking to me. Then a consultant named Mpho Moalusi is been trying to get hold of me. twice he got hold of me and it was during my teaching time and i told him to call me at 16h00 he agreed but never called during the agreed time. I am not allowed to leave learners and answer personal calls. even yesterday another female consultant called and left voice message because i couldn't answer the call. Mpho claimed to have called at 16h00 in one of the days but i never got a voice message or missed called at 16h00 from him. PLEASE CALL ME AFTER 15H30 ONWARD AND NOT BEFORE. How can something so simple be made complicated. This is unprofessional, unacceptable and inconveniencing to make customer struggle over such a simple query for so long. I hope i will be compensated with a discount for all the prolonged waiting i have gone through as a result of mere incompetence from staff.