Difficult... hold times are long - I waited up to 50 mins twice but once through, representatives are very helpful.

You can't! They hang up on you, absolutely terrible service

It's fairly easy and they have several ways - call, email, live chat. I do think they need to invest in a FREE phone number as often it is a query with something that they have got wrong so customers shouldn't have to pay such a premium to sort it out. Sometimes it costs more to sort out than the query or error made. Email them first but this isnt a fast route to an answer but they do get back to you.