My Account - Add-ons - 'Unable to change service' error message

[#1]

I'm trying to add a static IP to my account but I get the following error message:

Unable to change service

You can't change your products for the moment, you have an order which is currently being processed. Please try again later.

I'm also seeing this on the my account homepage:

An error has occurred

You can't change your products for the moment, you have an order which is currently being processed. Please try again later.

Its always been like this, I switched from Sky in December last year.

I've tried calling support but it's not possible to speak to anyone about this, the call just hangs up after mentioning this forum.

[#2]

Moderators Note

This topic has been moved from Fibre to My Account / Billing

[#3]

I have the same issue...    I can't speak to anyone on the phone, live chat is essentially a repeat of the phone experience, and My Account also says "

Unable to change service

You can't change your products for the moment, you have an order which is currently being processed. Please try again later."

If I look at the Order Tracker, it shows the final step as incomplete, although I've been paying by direct debit for a year.  Surely this would be an easy fix, if anyone could be persuaded to look at it?!

[#4]

I have since managed to speak to someone about this. I called in the evening last week.

They advised that there was some kind of ongoing problem with the dashboard but he was able to help me apply the add-on over the phone.