DSP rejection and short payments

Im writting on behalf of practice , we have a patient who has been pleading with medshield to put us on DSP as he is not willikg to change provider due to reasons he has given them on email and they told him that the provider must reapply. We have been doing that but they still reject us meaning they not being honest to patient that they don't want us as they cant give reasons why whereas patient gave them the reasons why he cannot change providers. On top of this they are busy underpaying us instead of R1796 after copayment they pay us 1077 and all consultants keeps saying its 40% copayment till i tell them to use a calculator then they see problem and apologize but this doesn't change they still pay new claims same amount and everytime i call its still same thing i have to argue with consultant before they can see the problem it's like you have to teach them how to calculate.