@Cam26
I don't know what to tell you. It has only happened to me twice, and those were both cancellations that Airbnb wrongly refunded under the COVID-19 EC policy, even though they didn't apply, e.g. they mistakenly refunded a guest for two weeks that she already stayed when there were no complaints nor problems.
In both cases, it took a month of constantly harassing CS until I got my money back. The only method I found that worked was to keep it very short, factual and simply quote their own policy back to them, i.e.
CS Rep: The refund was in line with our policy.
ME: No it wasn't. Your policy states "X, Y, Z".
Over and over and over until they relented and paid me back. Of course, it shouldn't be this way...
Any idea why this is happening? Because the reps are outsourced and trained to close a case as soon as possible and move on to the next so they would rather just refund that have a conversation about it. They are also allowed to say the decision is final even if they haven't addressed the actual questions/evidence, so again, it's easy for them to simply be done with it rather than investigate.