Looks like a good offer, amasyim is on fire with their offers.
http://cc.ebay.com/au/amaysim
Get $25 eBay voucher when you join amaysim.
amaysim offer – eBay Gift Voucher Terms and Conditions:
The voucher entitles you to $25 off the purchase price for one transaction (including postage) on eBay.com.au.
The voucher expires on 29 February 2016. Any redemption code which is not used by 23:59 (AEST) on 29 February 2016 will cease to be valid.
A limit of one (1) transaction per voucher applies. Multiple items can be purchased in one transaction (up to a maximum of 10 items per transaction).
There is no minimum spend for use of the voucher.
As jackofspade said, check the account payment status.
Mine failed at amaysim before due to cc failure, so then I bpayed. Then later told Bpay failed as it's less than $10. So then used Paypal option succesfully. Eeehhh! Lol.
However, I'd success, just start again. Pick a new number, use new cc card, email etc…
Much easier.