Mtn momo a big ****

I had made a payment of 816.00 in my mtn momo account for a disc renewal in September 2020 to avoid long ques at the traffic department. Mtn momo still has not sent my disc which I had to go renew manually. I call the call center a number of times but there is no reply because I want a refund. Judging by the numerous complaints about momo, I have reached the conclusion that it's a **** but it seems no one is doing anything about it.