Yes Peter, absolutely. That way, both you & the bank have a clear record of what's happening.
I know you did have problems before actually getting in contact with the exact department that were dealing with your case, but if at all possible it would be best to avoid phone contact, as it's too easy to be railroaded into agreeing to do something that you are unable to do. Once you have the details of the person/dept that is dealing with your case I'd advise written correspondence at all times. It gives you time to think & ask for advice should you need it.
If, by any chance you do receive a phone call, just say it's not convenient to talk at the moment & tell them to send any details or requests to you by post, & to include their exact postal address.