Cannot change my home phone call plan

[#1]

I want to change my home phone call plan from Plusnet Anytime to Unlimited UK and Mobiles but get the following message in my account -

"There's something we should mention... You cannot change your Home Phone product at the moment".

It looks like this is a common problem. Can someone fix this please?

[#2]

@denisb I've been looking into this and I believe I've spotted the issue but it's not something we can fix unfortunately however we can put the change through from our side so I've raised a support ticket on your account.

If you can respond to the ticket here with confirmation you're happy to go ahead I can arrange this for you