Won't accept payments from smaller banks

I don't understand how you can only accept payment from the 4 big banks in South Africa when there are other banks who also provide online payment services. So now I am forced to use a bank I don't want to use so I can pay for your service. It makes no sense considering the size of your company. You not receiving payment from TymeBank for instance leaves out many customers who potentially want to use your services but can't because payments from TymeBank are not recognised. Is this not some kind of prejudice when you exclude other customers? Some of us have moved away from the big 4 banks because we don't want to bank with them anymore and your decision not to accept payments from other banks is outdated.