Broken account.

My Virgin Media account is broken; it does not let me make any changes.
I have tried the website, app, a different browser. It makes no difference.

Anytime I try to make a change, it says "Sorry! You are not eligible for this particular offer. Unfortunately you have missed out on this offer but we have plenty of other offerings that you could be interested in."

It does not matter if I am trying to upgrade my broadband speed, upgrade TV, manage My Flex Plan, upgrade to Volt etc, no matter what I try it redirects to the following URL and gives the above error. https://www.virginmedia.com/support/help/change-my-package/my-current-package/offers

I recently contracted (had the same issue beforehand) and spent quite a while on the phone trying to get this sorted out, but nobody could help me with the issue. At the time, I didn't realise the problems with changing the My Flex Plan, so I figured that while I did want to upgrade to 2Gbps internet, I would stay on the 1Gbps as it wasn't worth the hassle.

Something needs to be done to fix my account, and nobody on the phone was able to help, so where do I go from here? I don't care if the account needs to be deleted and set up again, something needs to be done as it can't be left like this!