Please Help me resolve the dispute between myself and G-Pac Auto Motive

I took my car for fixing oil and water leakage in January 2023, they promised me that they will fix my car in no time. I kept on contacting them to get update on the progress made, and they keep on giving me excuses indicating that they will call me when they are done. They then call me towards the end of August 2023 telling me that they have fixed the car. I then went there to their workshop payed them and left. The next day when I move out of the garage there was the oil stain on the floor. I then immediately drove to their workshop and indicated that car still has oil leakage. I left the car with them to fix it. In December 2023 they then call me and tell me they are done. Once again I went there to collect the car. On my way back home I went to the filling station for petrol and I decided open the bonnet to check water and oil level, to my surprise I discover that they have glued the sponge on the car bottom car cover that protect the engine. I immediately call them and ask them why they have glued the sponge underneath the car, they failed to give me a clear answer. The following they when I check on the garage floor there was the oil stain. In January 2024 I took the car back once again. I kept on checking up until the End of September 20224 when they confirmed that it will be ready on the first week of October 2024. In October 2024 when i went there to collect my car they told me that I have to pay again for fixing the oil leak . I asked them why should I pay them twice for the same job. They then keep on insisting that I must pay them or else I am not getting my car. I then ask them to check if the car is no longer leaking oil. We took a car for a long drive and upon return the car was still having some leakages. They then said they will attend to that I must give them few days. A week later I went back, when I get the person who was fixing the car sail they are still waiting for the pipe the was leaking as they have send it some were to be fixed and he said I must give him few minutes he is going there to collect it and he never returned. I went home, after some few days I went back , when I get there they said the car is ready but like they said before I must pay again for the work they have done. So I am having a challenge as why should I pay for the same job twice. Please come to my rescue.