you wait till your money get refunded in to your bank account and once you received your money you can buy the item again.
but this time make sure that seller ships the item with in the deadline.
if seller asks you to wait for longer time (usually seller has 5 days to ship the item) if sellers crosses this time period you yourself open a case going to reslution center and leaving NEGATIVE feedback to him.
http://resolutioncentre.ebay.in/
you have to do it , because some sellers are more reckless.