That site said free shipping on orders over £60 on the top. If you read the delivery details page it was actually on orders over £75.

I wasn't going to argue the toss with them but I selected free delivery anyway for my £62.75 order and they honoured it. 

 @d4b81373 this be why offer thresholds are always round numbers but prices never are. 

 @86cc0286 It's probably why I have too much PTFE tape.