Help with incorrect phone number

Apologies if this is the wrong forum, im not sure what else to do.

My old phone died rather suddenly. Can't even turn it on whilst plugged in kind of died. So I got a new phone and got to the point of setting up my google account on that phone.

The set up said to use another device, so I used my laptop, which then required me to have my phone number to set up. The issue is that said number isn't mine. I have no idea who's phone number that is, but I have had the phone number I am currently using longer than I have had my google account.

So I tried to change the number, but it seems to require you to either have access to a previously linked device (said very dead phone) or access to that number (which isn't mine). Every link I can see on the google account seems to take me to one of those two suggestions.

I can access my registered email etc and all of my other services on my laptop just fine and have other ways I can hypothetically prove to google that I am who I say I am, but I have no idea how further to proceed. I have put a question into the help desk but both haven't recieved a response and every related question I could find also never recieved a response.