What sort of restriction do you have? If you're only restricted from selling, you should be able to buy on eBay and contact sellers in the usual way.
If you have been restricted from both buying and selling, I don't know what you would do. My guess is that eBay will tell the seller not to send the item, unless they have already done so.
If eBay customer support has not contcted you, you may need to contct them.
