This is why it is infuriating. They have some model and some threshold. If an account goes over the threshold, they're banned.
For whatever reason, OP ends up over the threshold, and eBay is completely unwilling to put any customer service effort into reviewing whether they model may have misclassified OP's account. Having the service be completely off limits for a certain % of companies because it's too hard to assess errors is part of the business strategy, and it's an absolutely awful experience for the small number of people it affects.
Luckily, OP can probably live without eBay. Now imagine what happens in scenarios like these, which show up every few weeks on HN and other news media.
1. Sellers who make a living off sites like eBay who have their livelihood thrashed when model goes Beep on their account for some reason.
2. Businesses (and their customers) that rely upon cloud services that have their accounts closed indefinitely for unspecified reasons.
3. People locked out of their Gmail/similar accounts for unspecified reasons, who then lose access to every account tied to those accounts.
If you've ever been in one of these situations, it turns into a Kafkaesque dystopian runaround at best, and complete blackout at worst. I ended upon on the wrong end of an indefinite suspension from Google. I had to appeal a dozen times with no insight from them. I ultimately tracked it down to an off-by-one error on a payment card zip code. I had moved across town and my zipcode went up by one. Google didn't like that and I was a threat until I figured it out. Took months.