Virgin Media have got hold of the wrong end of the stick.
You've been able to log on and post this question, so you're not blocked.
It's more likely that you've tried to bid on something, to be told that the seller has blocked you from bidding. This won't be personal, and it has nothing to do with your IP address. It simply means you don't meet one of the criteria that the seller has set for bidders.
If you want to give a bit more detail about the problem someone here can probably advise you.
