How can you not pay for Astomy products?

My brother is physically disabled from shoulder to toe due to an accident.He was put on CHRONIC for Stoma products ,now we cant order products WITH MEDICAL AID from the Supplier which is COLOPLAST ,they say we must pay cash and its not just him ,but they are not servicing all SizweHosmed clients with medical aid they are requesting cash . These products cost thousands of rands how is that suppose to happen when he is already paying close to R5000 on medical aid . There is not even a choice of using nappies when a person has done this surgery. This is such a disgrace on such a delicate situation ,what are we suppose to do .