Poor workmanship

I recently bought a Suzuki bandit 400, I took the motorbike to Bikerswharehouse to be fixed as I was experiencing carburetor issues. I first received a estimated quote from bikers warehouse on the 1st December 2020 of an amount of R2920.15 which I agreed to.

The bike stayed over night, after which I received a email to tell me that they won’t be offering any workmanship or garentee on the work that was done, shortly after I received a invoice for R3037.30 which I had to pay so that my bike could be released to me.

I drove the bike for 2 days to we’re my problems came back, Bikerswharehouse had informed me that I have a problematic bike (this I know, I wouldn’t have sent it to them if it wasn’t) and that parts were damaged, to which they didn’t offer replacement of, they only advised me to go buy a second hand carburetor as Suzuki did not have stock of.

I was forced to pay for something that at the end of the day I did not benefit from, money thrown away due to no garentee, I had no say in the matter as it was not communicated with me prior to the invoice.

Now is this not bad workmanship as I have to pay again for my replacement carburetor to be installed?

I require compensation or 50% refund on the amount paid because I feel that this is not right and ripping someone off in the manner they did is unacceptable!