Are you in the uk? if you are, you're supposed to be able to see the business seller details if you're a registered business seller. I didn't think you were allowed to hide your contact info when you were a business on the Uk ebay site. I am surprised that whoever you spoke to at ebay wasn't aware of that. Found this on their site too:
"Please note that business sellers on eBay.co.uk are required by the Electronic Commerce (EC Directive) Regulations 2002 to display their contact details"
I have a friend who sells on the UK site, and he had to register and all that--that's just the way it is there. If you're using australia, i'm not sure if they have the same regulations or not. Easy enough to find out though by searching their help info.
Am very sorry about your ebay account getting hijacked. I get those spoof-phishing emails all the time from one site or another to update my account or whatever their line is to try and get my id or other personal information. Sometimes is a bank, other times paypal...One day it will be widespread knowledge to never ever ever click on those, but the spoofers make them look VERY legitimate and real. but until then accounts will continue to be taken over. Hopefully you won't incur too many problems and ebay will get it all straightened out for you. Best of luck!