failed to take responsibilty of poor workmanship

Jan 2015 mazda bruma services car replaced sump washer valve. May 16 sump plug falls out not tightened properly- they fail to repair at their cost and quoted R145000 for a bearing knock -car stood there for a month as they said I fell out of the 3500km workmanship guarentee not even a mazda SA policy but service guarentee is 12 months so I moved it to another workshop-after a meeting with mazda SA it was decided they would tow it back to bruma repair the damages and cost would incur if parts not due to damage caused by problem needed replacement or repairs. After they towed it back to bruma fully striped they said they would not fix it as a foreign oil filter was on.the other merchanic obviously took it off when he striped the car. They insinuated that someone else serviced the car - how can a second service be done in 5 months? A week later they wanted to charge me R800 storage fee. I removed my car from their premises and now have to pay for their damages out of my pocket. They inconvieniced my life 5 months and lack customer care skills.