No need to apologize, your frustration is valid and I'm sure no one would on this forum would blame you for it. Sorry to hear about your troubles, sounds like it's a mess. A 10" x 10" hole is significant.
Did you by chance pay them by Credit Card? You may have rights under section 75 of the Consumer Credit Act 1974; That will get their attention.
Don't get too disheartened about insurance companies being naive, it's not unusual. Just get quotes and description of damage from one or two respected tube specialist, the insurance company could then use that information & numbers to file your claim; just bear in mind that your tubes are 12 years old and will effect valuation.
Hopefully things will get worked out properly and get you back on the water promptly.
There're several excellent retube companies that you could go to and depends where you are located. Prices will vary. I'm sure others on this forum can give other recommendations but here are a couple to start out with. I'm sure I'm missing a bunch of other good companies.
Henshaw has a very good reputation:
RIB tubes, RIB collars, yacht fenders and much more - Henshaw Inflatables Ltd
Rib Shop, I believe they use Henshaw tubes but are price competitive:
Bombard Rib tubes - Rib Shop Ltd
Venture Marine Ltd
RIB Tubes and RIB Repair - Tilley Inflatable Design and Engineering Ltd - Marine Engineers - Dartmouth Devon Plymouth Cornwall South West UK
For one, XS Ribs quotes on there website for 6m tubes is £4K with Hypalon. However I'm pretty sure Bombard was either PU or PVC.
Retube Refit Inflatable Boats Humber Ribcraft Avon Zodiac Collar Tube