Kwik fit damaged my car

I took my car a Range Rover evogue Petrol for a minor service and wheelbearing change.that took three days because they ordered a gasket for the manifolds and turbogasket. They charged me R 11 000 for the job.I paid, however my car had a sudden oil leak, the car would not drive, it started misfiring and cutting off while driving and they said it's not their fault. I was told to take it next door where they would fix it. I refused and told them it's their cost.they tried something on my car I drove the car I eventually got stuck 200km away from them .the car had no issues prior to them working on the car.They insist its an old problem which I deny as the truth, I now want them to resolve this matter as soon as possible.I am stuck very far from home now