Complain / dissatisfied

I purchased a 2year/2service plan with innovation for R6900, my first service was okay. but on my last service they refuse to pay the total amount for the service, claiming the the garage has inflated the prices. first service R3200, second service R2900. the y refused to pay the full amount and i was then liable for the balance (of a product i purchased)? I would like to inform and educate my African black brothers and sisters to avoid purchasing these products from innovation or any White Insurance company as they are mandated to give them problems during claiming while white people have none of the wrongs we constantly face with these insurers. rather pay the monthly subscription into a savings account.