Quote scam

I took my car to Mtek a division of Marx motors for repairs. I asked for quote, they quoted me R44 thousand rands. I got another company to do the same job for R6 thousand. when I went back to Mtek workshop for my car they asked me to pay before I could get my car back because they already made a quote for it. My question to them was, why didn't you tell me before making the quote that the quote comes with a price and then I can make informed decision. right now they have seized my car until I pay. This company is a scam!