The refund will not be backdated to the date of sale but will be dated from when they notify a refund is on the way. And the initial payment would have been processed as a CC transaction so the refund will as well. Sometimes it can take a while for the bank to process. My refunds are usually within 10 business days at most (nab/ visa), sometimes as quickly as 3.  If you did want to contact eBay try the livechat or you could check with your bank