What to do about Discovery?

My doctor friend who sent me the letter about Discovery raised some interesting observations. Some of these practices have been going on for some time. For example, if I buy a pair of prescription glasses for R1000, Discovery shows the claim of R1000 and deducts R1000 from my medical aid, but it only pays Torga Optical R850 because it is "entitled" to a 15% "settlement discount", AND it keeps the R150 that it deducted from my account.
What do you do if you're a supplier? The choices are simple: make yourself unpopular with your clients by forcing them to pay you first, and then claim from Discovery after that, or claim from Discovery directly and lose out. But are these the only choices?
The programmer in me says no. The programmer in me says that I should screw up Discovery's computer system by claiming the undiscounted amount, and keep on claiming until their system breaks.
Here's how it works: the patient P goes to see the doctor D for a 1 hour consultation, which D charges at R200. When D sends the claim to the medical aid he is supposed to only claim R170. So D claims R200, and the claim is processed and pays out R170 to D. D then claims R30, which is then rejected, and the rejected amount shows on P's statement. Once the R30 is rejected, D claims the full R200, which is then rejected as a duplicate claim, and it appears on P's statement as a duplicate claim. Every month thereafter D claims the full R200 again, and each time the amount is rejected.
Next time P comes to D, he is informed that he owes D R30 for the amount that Discovery didn't pay. Assuming that P visits D 3 times a year, by the end of the year there will be 4 paid claims, and around 22 duplicate or invalid claims, and D will be short by around R120. If D wanted to be unethical he could schedule an appointment that P doesn't keep, and claim another R170, which would cover the additional administration costs and interest. Or he could keep P waiting for longer than 1 hour and charge for 2 hours.
My doctor friend wouldn't do something that might be regarded as unethical, but it sure is tempting. I guess the best way to deal with Discovery is to buy shares in the company and raise a stink at the next shareholders' meeting. Perhaps I should do it for him.