CMH EAST Rand, Ripped Me off???

My Name is Thando Sibiya, I took my car for service and repairs at CMH Eastrand on the 26/11/18. I was being assisted by Mahlodi. My service was covered by motorite and it was R4071.25 which i was ok with. I specifically told the lady whom was assisting me the faults which I picked up on the car and that they must just do an overall diagnosis then quote me. She call me later that afternoon with a quotation of R18446.38. When she gave the quote I still asked if this will fix all the issues with the car and she said yes. I asked when I can make payment and she rep**** upon collection is fine. They then called me Friday(30/11/18)afternoon to say my car was ready. I went on Saturday(01/12/18) to pick it up and paid the R18446.38. I was told about the 12 months warranty on the work done. The next day when I started my car i had the same fault they apparently fixed but it was a Sunday(02/12/18) so I planned to call them the Monday. On Monday they called me first to rate satisfaction and I told the lady I spoke to that I still had one of the faults I mentioned when bringing the car in. She said I must bring it whenever I can they will check it out. Obviously I’m working 6 days a week and couldn’t spare time but had planned to bring it on My off day(12/12/18), but as I was driving on Tuesday (11/12/18) the car just cut and luckily I was close to the garage and I could it check it out there. I opened the bonnet and the was water all over my engine. I called CMH east rand and spoke to Mahlodi who told me they don’t tow cars so I must make a plan to bring it and after paying so much money that’s what I get as a response to my problem. Anyway I called my insurance company and made plans to bring it to them the next day. I brought the car on the 12/12/18 towed by my insurance company not them, they called me later to tell me I’m gonna have to pay as this is a different fault they finding. I asked them how can I pay after I told you guys to diagnose the whole car and quote. I paid all that I was quoted and after one week my car is stuck on the road. What service is this? I want my car fixed, they ripped me off. CMH east rand stole my money and provided **** service, they messed up my car and now they won’t fix it but demand more money. I want justice, they can’t get away with this.