You are right that this has reached a stalemate.
You pointed out "maybe Desmond should just give you the amount he offered and forget about removing the installed items". Since 2 out of 3 of the items/ solutions cannot be removed shouldn't this be the case? Its not that I want to keep his "PROVEN" solutions that dont work for me anyways, I can always get another installer to remove this "PROVEN solutions from my car" and return them to him if its removable for a refund.
While you call this an endless loop of bickering, I think any readers with an open mind can conclude from this bickering (at least in my case) of this FACTS raised:-
1) KL Auto is a braggart/ misleading/ false advertiser (words like PROVEN SOLUTIONS/ R&D Team/ BEST is used extensively but could not be substantiated)
2) After sales service is non-existent even if you are not happy/ satisfied with their work (excuses like their phone and records will be lost)
3) If you actually bring your vehicle back and confront DC and his team, they will retweak their "solutions" for you. It may takes years with little or no improvement (unless you buy more solutions and make KL Auto richer) and waste your own time.
3) Recommendations/ Solutions from KL Auto is inconsistent even if you have same problem/ same model of vehicle.
4) Most products put into your car by KL Auto cannot be removed and hence the justification for partial or no refund.
5) The AUTOFOAM application is not administered professionally as claimed with measurements etc. It will just sprayed into your vehicle from re-branded bottles (The original brand is Wurth???) until it seeps out. Side effects will include expansion of the the autofoam into your car's suspension/ timing belts/ other parts and may cause further and new problems.
Well, I have shared more than enough of my actual undisputed sad experience here with KL AUTO and confirm that the "win-win solution" offered would be either to be cheated and suffer in silence OR speaking up and sharing this sad findings here hopefully cautioning some readers of future dealings with KL Auto.
From an owners point of view, I definitely would not want someone whom I no longer trust to further work on my car so I can understand your unwillingness to let KL Auto to further work on the car. In other words, the only working solution for you is to leave the products in your car but take a reduced refund. But it's hard to imagine any seller would agree to doing that though :/
Btw, if quietdrive is a paint-on application product, then I *think* it should be removable either via industrial solvents or by scrapping it off, with the latter solution being very undesirable and unfeasible.
Good luck, I hope both you and Desmond can somehow arrive to an amicable solution soon.