Medihelp - fund rules and discretionary decisions

My elderly dad's prescription for chronic meds changed; he is now using a LOWER dosage of one of the medications. Medihelp is refusing to pay the last month's prescription because of the change. It's not just the one drug that's in question here, none of the other meds were paid for by the fund. We're in the process of sending them the new prescription, but regardless of this, they're not willing to pay for what was already claimed/issued by the pharmacy. I was told by the agent (Linda) that this is fund rules. So there's absolutely no room for discretionary decisions at Medihelp. Come end of the month they will gladly assist by taking your money.