Plusnet lost my emails by mistake

[#1]

I have just moved ISP from plusnet to BT. However I asked Plusnet to keep my email account open and a ticket was raised for this. However today they accidentally closed down my email address. Although this was resolved it meant that all my emails were lost. I had about 100 emails going back 4 months and they are now gone.
Plusnet are saying that they can not recover them and that it is my responsibility to back them up - even though it was there mistake that led to this.

[#2]

It is not PlusNet's Responsibility to keep a backup of your e-mail's it is yours and yours alone to backup your e-mail's.
But if you ask nicely Bob Pullen may be able to help you.

[#3]

@kevinjbolton
I'm really sorry to hear about that mistake. Needless to say I'll make sure it's fed back that this has caused you some inconvenience.
I've just looked at your account and can see on ticket 52138876 that we've already checked the backups for you and we've not been able to locate anything.

[#4]

Surely if you used a normal e mail programme eg Thunderbird, rather than webmail, you'd have them on
your PC, where you could have also made back ups to a zip drive/USB Stick/ SD card etc.