Bad service

I bought a whole treatment of Fitolium of which has cost me R2600 while taking the treatment I experience some stomach pains and diarrhea when I lodge a complaint from the platform that I've used to purchase the product they gave me a number to call and an email I've tried to contact both of them without any success. When I contact the whattsup that I've used to place an order they said their just middle man now I need a refund because I can't keep on using this medication it makes me sick