Just pay the delivery charge. Download the app, find a bottle of wine on this app for £15 and just pay the delivery charge. You can use the code to get £15 off any bottle so you can choose one that's more expensive and get £15 off or one that's cheaper.
Bottles under £15 have a surcharge on them so your best bet is to find one for £15 or just over and then you only have to pay a little bit and the delivery. Hurry because this won't last long.