Not happy with M-sure service really disappointing

Always when I take the car in for repairs I have to pay the whole amount the service providers tell me that m- sure does not cover even the things that should be covered I pay with my cash and when I have to claim back from them they would say that the job done they don't cover, I'm very not happy with them even when you make a follow up email on claims sent to them by me they just ignore as if nothing was sent to them theh really frustrate me