"I was assured that moving to an email only account was a simple matter and that I would definitely not lose my email history. I would have backed up all of my email had someone been honest and said there was a risk of losing all of my history."
This is a very important point, which Plusnet should be stressing to anyone moving to an email-only account. ALWAYS BACKUP YOUR EMAIL HISTORY. I did this by selecting all the emails in the Inbox, selecting "Copy" rather than "Move", and putting them in a temp Inbox in Local Folders.
As it happens, Plusnet eventually got all my email history back, so I just deleted all the copies. I didn't think of this until after the problems started, but thankfully before an empty Inbox appeared; I was worried that the local copies in my Inbox (I use IMAP) would all have disappeared in that case!
I do hope Plusnet get their act together. Communication between back office staff seems to be extremely poor. I was told completely contradictory (and wrong) things by some staff. Someone eventually sorted it though. Hope that works for you!
