Ridderhoff for bad Service

I took my Chevy Aveo there with a broken cambelt. They stripped the engine . replaced bend valves and broken valve lifters. I paid R7000.00 . got my car back with a knocking noisen the engine, the engine jerks and misfire . They tell me it is bearings. Were they not supposed to check the whole engine for damage. They refuse to fix it. I spend another R3000.00 at another repairman on replacing bearings . the vehicle still makes the same noise and jerks. Please people never take your vehicles there.