I am an attorney, not in your JX.
This is not legal advice and does not constitute representation.
From a legal standpoint, the contract/service agreement/repair order that you signed would trump the common law obligations created by bailment....subject to particular laws of your jx.... and "trump" doesn't necessarily mean reduce or minimize, it simply means that the executed contract/service agreement/repair order establishes both parties rights and duties. I would hazard a guess that the contract/service agreement/repair order has enforceable disclaimers absent gross negligence or willful intent to create a rat problem.
From a customer service standpoint, I'd think the establishment would offer more than $100....but perhaps their margins don't justify more and they'd rather lose the business.
From a practical standpoint, don't engage an attorney...not worth the $$, time, or hassle. Your idea to simply take your business elsewhere in the future makes the most sense.