I'm sorry, I don't have an answer to your question directly. All I can tell you is how I'm managing as a resident of a Scottish isle who also struggles with businesses refusing delivery to my locale.

Unfortunately I've not been able to cut Amazon out entirely but I have managed to relegate them to a retailer of last resort. I've not found another find-everything store and instead go to different retailers for different needs.

Usually I start local, on my high street beginning with charity shops that support local causes before buying new (there's one that supports my local food bank so I try there first). If I can't find it there I widen my search to retailers on the mainland. Failing that, I broaden my search to retailers in the UK, then the EU, and only will I consider Amazon once I've exhausted all other options. Even then, sometimes its possible to buy the product I find on Amazon off Amazon (think OEMs who use Amazon as retail channel) by going to their website and buying from them directly.

Sometimes I still have to rely on Amazon but I have managed to cut my shopping with them down from sometimes multiple times a month to a couple times a year. Of course it largely depends on what I'm shopping for, but it was definitely an adjustment to break myself from the one-stop shopping experience Amazon provides.

I hope this is helpful.