Sounds like a virus to me. First thing I would try is turning off the computer for a minute before turning it back on. If that doesn't work, I would run a virus scan. Some viruses are designed just to annoy, or damage a business.
Edit: I just Googled and it appears this isn't a virus. A block typically lasts 7 days. Here are some discussions that may help. (Google for even more info.)
https://www.thewholesaleforums.co.uk...ed-out.157493/
https://community.ebay.com/t5/Member...qaq-p/27594357
https://community.ebay.com/t5/Member...qaq-p/24589230
https://community.ebay.com/t5/Member...qaq-p/27616189
Looks like you will regain access after 7 days. Meanwhile, it may be a matter of which phone number you can find to call to resolve the issue sooner.