IP Complaint – How do I get access back to my ASIN? (To liquidate / remove inventory)

A competitor (large corp) opened a IP Complaint on my ASIN, and the detail page has been removed.

I have 419 units stuck in FBA, they’re not letting me remove nor liquidate them (inventory “unavailable” when I try to do either).

They opened up a “Trade Dress” IP complaint – they have a trademark (image) on the product, so technically they’re complaint is incorrect (I’m not using they’re logo, their trade dress is literally the product, it’s hard to explain, but they can’t stop me from selling the product unless they have a utility patent, which for them expired 2 years ago).

I don’t plan on selling this item long term, I’ve been planning on stepping away from Amazon either way – I just need to get rid of the inventory in FBA to avoid long term fees, etc. But like I said, Amazon isn’t letting me move the inventory, nor are they responding to my requests about this issue (opened case last week, still open and “transferring” to another department).

How should I respond to the IP Complaint?

Should I just write an “apology” letter, stating I won’t sell it anymore?

Or notify them that this is a Trade Dress issue, and I’m not infringing on their trade dress? (And possibly be able to sell the rest of the 419 units, within 1-2 months, to avoid removal fees?)

A helpful person who used to work within Amazon told me I would need a “Letter of Opinion” from a lawyer for them to recognize that I’m right in this case.

However, I can’t afford to pay a lawyer $250 for a Letter of Opinion, I just want to get out of Amazon, spending the least as possible.

What’s the best course of action in my case?