Whining sound after timing belt change

I think your approach is spot on, they had multiple opportunities to make it right and refused.

There are additional problems, will the credit card company get your money back for you, some will but that is usually more work on your part.

The issue with the court system is you WILL be there all day as will they if they show, lost time and wages, this is where you have an opportunity to explain what is going to happen, see below... you will get a judgement in your favor as that is the nature of the courts. Collecting is another story. You are going to HAVE to be an asshole when it comes to this and this is against most peoples nature... the threat that needs to be made clear to them is that there is a proceedure to collecting and that is the Judgement Debtors examination. You apply for this and pay the fees. The court will issue a summons for a responsible party from the shop to show up and explain why they have not paid the judgement. The court has the power to litterly take the money he/she/they have on their person and with a baliff, walk to the nearest ATM and force them to take money out. If they dont show which is a Failure to Appear (FTA) to a court order, they will at your insistance issue a bench warrant in the name of the responsible party. Some evening the resposible party will have a broken tail light, and they will get stopped by a local LEO and the warrant will show when they do a wants and warrants search, they will get arrested, their car towed and impounded. This is the threat you explain to them. A smart person will pay immediatly.

This is the proceedure in CA when I have been forced to use it sone 10 years ago, other states are similar, there are self help books that are state specific and if you are serious I suggest you educate yourself. Is this a pain in the rear, yes.