Seller Central - No inventory but still available to purchase!

We've been receiving orders for a product we know is out of stock and seller central knows its out of stock (OOS since March 30th) but on the front end of Amazon they were still available to buy!

Has anyone had this issue before and does anyone have any moderators they can tag to get this looked into?

I have tried to contact them via different cases and we are getting no where with resolving the issue. If we cancel orders, we get a defect, if we ship late, defect. The issue is clearly not with our inventory upload via API as seller central shows 0 and has done for a week but we've still sold over 50 units of the ASIN.

I have had to close the listing today but that doesn't help with the units already purchased.