An email works as well as a phone call and gives you a better 'paper trail' (if acknowledged or replied to). A phone call will give them the opportunity to ask and further questions --- but they could deny it was ever made if there are issues later on. CF are particularly bad at communications ... maybe the old 'snail mail' (registered delivery) would be better !
My opinions are merely that .. opinions based on experience. Always seek professional advice.
IVA Completed 23rd July 2013 .... C.C. 10th January 2014 http://foggy.blogs.iva.co.uk
It is always better to keep an email as proof that you have contacted them and also, if you back it up with snail mail (registered as Foggy says) then you have double proof that you have contacted them.
Sharing from experiences of dealing with debt
The greatness of a man is not in how much wealth he acquires, but in his integrity and his ability to affect those around him positively.
Bob Marley. http://kallis3.blogs.iva.co.uk