I had a similar issue selling game codes a while back. If the buyer doesn't receive a tangible item then ebay forbids (or at least forbade at the time) selling of these items because there is no way to prove they were delivered. So Ebay cancelled my items and sent me a stern message about listing practices. Meanwhile there were literally hundreds of other similar listings live on the site, same as mine was.
Whomever you spoke with on the phone is probably not authorized to remove listings in bulk and would need to probably spend time on each listing and not on the phone. Moreover, yours was probably removed due to a specific complaint from a user. Your complaining about all the listings was probably considered just retaliatory and not followed up on.
I don't work there, but from dealing with them since the 90's (God I'm OLD) I see this as their M.O. To answer your question about suing, it would be an expensive uphill battle on your part and probably get you nowhere since it's their platform and can do most anything they want so long as it's legal. And let's be honest, the only pain you received was to your ego.