They serviced my car, after a day it was overheati

I took my car to Renault Polokwane for 45000km service on the 27 August 2015, on the 28 August 2015 when my husband was driving it to Pretoria it started overheating. He stopped after the 2nd toll gate to PTA and called road assistance and they promised to send someone from Pretoria. He waited there for an hour and called again and he was told that they can't find a standby technician. He then called his friend to come and tow him to Mokopane and he paid him R350. The following day he asked another friend to take him to Renault Mokopane to ask them to fix it and they fixed it without giving him hard time. I phoned the service manager after a week to complain about their service. He asked me where the vehicle was I told him that my husband is using it and he denied that the vehicle was overheating and told me there was no way he could drive it if it was overheating. I told him that he had to tow it to Mokopane and the technicians there fixed it, he did not believe me as if I was lying to him and promised to call Mokopane service manager. I wrote my complaint to national Renault website beginning September, they only called me last week to check if the vehicle is fine.