If you have your publisher ID still, you're best bet is to contact them via email and ask to reinstate. You should also provide a link to the website you'll be using them on to be more convincing.
Thats all you do is just go to their website and contact them there might be a really small chance you will have to reapply but if you are in the US then you should get auto approved. But the down side is that you will have to apply to the merchants you want to use if you had them before.....