I needed to cancel a RFS and I couldn't do it online. I was told because it was only a Y one way that had a £15 fee because this was less than the £25 cancellation charge you can't cancel it online and the contact centre need to do it for you. Avois were redposited within a few minutes and the £15 forfeited.

On a return RFS I got the option to change flights date and time for the fee of £25.. I am guessing this is due to the fact that the minimum cancellation charge of £25 has been more than covered by the £30 booking fee.