Gems refuse to reimburse our claims

Gems does not want to reimburse me for claims submitted. I regularly visit a Chiropractor in Kensington, Dr Molefe Shai, pay cash and receive an invoice. Gems was paying every time I submitted the invoices. In December I visited the practice again on several days with my wife and child and paid cash for all our consultations. I submitted the invoices several times but Gems has been rejecting them. The reasons varied from "practice number not on invoices" to "valid proof of payment not submitted". I am at my wits end and have no option but to seek redress elsewhere. I was on Onyx and contributing almost R10 000 monthly.