Non payment Healthygear benefit

Discovery is doing everything in their power not to pay me the Healthygear benefit offered on their website . First they had apparently "linked the wrong card" to me and nothing could be done as the transactions were irrecoverable. Unfortunately for them I still had the till slips to prove my purchases. So now they captured these wrong and refuse to correct their mistake. I ended up receiving less than half the cash back benefit I am entitled to. In my opinion nothing but another ****.