Extreme Disappointment with Purchase of Sales Vehicle and After Service

we bought a car Toyota halfway Promenade in 2016. The car has been giving problems ever since. The tyres are producing an unbearable noise. we took the car in on numerous occasions to be checked out and every time the reply from the service department was "no mam there's nothing wrong with the car ". Until one day me and my family were on our way to George for a holiday and we got a tyre burst while still driving. both mat flaps of the tyre that burst was burnt, cant be used again. while my husband was changing the tyre I was on the phone talking to Zoe which sold the car to me and explained the whole situation to her and she said "that isn't her problem we need to sort it out". when we returned back to cape town I logged a formal complain to Mr. Wood the principal dealer at halfway Toyota Ottery. the problem with the tyres is still not resolved.