Addresses do not expire. Addresses are not linked to a transaction. The site simply means that they will no longer actively watch for a payment to that address so they will not mark your order as paid. You will have to contact their support in order to fix that issue. Bitcoin transactions are not reversible so if your transaction confirms, you will not be refunded. You must ask them to either refund you or proceed with the order.
Your transaction has not confirmed because the fee is too low. You paid a fee of 7390 satoshis (~32 satoshis per byte). A fee that will allow your transaction to confirm within one block would be 20160 satoshis (90 satoshis / byte) according to
http://bitcoinfees.21.co/.
54e47d2a553f1e4c424c08139610d536ea8fbe0d8b8163ecab3166a190b14e4c
This transaction depends upon your first unconfirmed transaction. It cannot confirm until the first one does.
655c007e1927895c3c434a4c0c6ac39d5b03a0aa1a662eba7e18c9b209df6030
The fee is too low on this one.
i use electrum which automatically works out fees so dont think its that and have never had this problem before....
With Electrum, you can set it to use dynamic fees (it figures out the best for you) by going to Tools > Preferences and checking the Dynamic Fees checkbox. To get the fastest transactions, move the fee multiplier slider to the right so that the fee you pay is higher thus your transaction confirms faster.