Hi @Tenawee,
Welcome to the Community!
I'm so sorry to hear about the trouble you're having when trying to upgrade online, as I appreciate this is far from ideal.
When you've spoken with our team have you logged a complaint and had this flagged as an issue?
It may be worth getting back in touch with the team so they are able to do this, and potentially upgrading over the phone, so you can get your new plan sorted.
Rach
