Charging for no service delivered

Needed a V belt replaced as informed by kia -they requested a deposit of 50% upfront, yet Im purchased the vehicle from them for R300k+ ?? They said they were having a problem fitting the belt, so sent the K2500 back to do the job after -they didnt inform, me and requested payment -which we did - now they say Kia does not have stock? Blatant lies and **** service -so sorry I bought the car