Warrant cover

I had AUDI RS5 2012 MODEL had problems with gear box ,,I had to refer the car to Gearbox Center Durban and it costed 70 000 incl vat ,,MVIA only paid 3700 excl vat ,,I had to pay 45 000 including vat of the total amount which is 70 000, meaning I had to pay 54 000 .Even though their Warranty cover was supposed to pay 70 000 ..😪😪