Unsatisfactory Service to Motor Vehicle

My vehicle was sent through for repairs after an accident on 11/10/14 to North City. Thereafter, I started finding faults on a daily use. Now there are electrical faults which we noticed from Dec'14. I did complain to Miway but this complaint has not been attended to. The fuel gauge reads incorrect, clock goes off, radio station jumps, it locks & unlocks electrically when it wishes to, which can cause an easy theft or break in into the car & noise on reverse. Car insured for R120k but repairs came to R80k without interference of the engine nor the electrical. A back door would have charged about R30k for a better job. Please attend to this query seriously & urgently. Miway stands responsible for THEFT or BREAK IN to my car. Thank u!