Brake pads not changed

I had a bad experience with Autoguard. I joined the service plan in 2018. An additional amount was added for brake pads. When I took my car for 90000km and 105000km service, brake pads were not changed. I send an email stating that I them changed and there was no reply. This month (July) 2019, my car started to make a weird noise. I called the company and was told that my sales representative had left the company and that they believe that my service plan covers only the front brake pads as the rep added a small amount of money for brakes and the reason would be that he might have called Hyundai and was told that my car had only front brakes. When I went through my email, the guy who was assisting me by the name Sne Khumalo is my sales representative and according to all documentation my car model is clearly stated and that it covers all the brakes. The company wants to do only the front ones and I have to pay for them and they will reimburse me. I seriously need help on how to go about with the matter.