did you check unbilled credit amount using NetBanking account?
when you purchase something on EMI they just block the full amount of your payment but charge you on monthly basis. for eg. you make purchase of 30,000 on 6 month EMI and your credit limit is about 1,20,000. they will block 30,000 from your credit limit but will bill you only 5,000 every month.
or
it can be eBay system issue, they might charge you full amount.
since i have purchased 2 items until now on EMI base, i never got full billing amount. i was charged regularly only the EMI amount.