Check out failure when change energy plans

[WingMP]

I am an existing AGL customer and would like to change both my electricity and gas plan (residential). I went to "change energy plans" on my online account. Then, selected new plan for both electricity and gas. However, when I clicked "Express Checkout", the page gives me the following error:
"Sorry, something's gone wrong. We're having some issues accessing the right data. Please try reloading the page or Contact us, for help."

Then, I contact your staff with the online chat.  It took me more than 3 hours to communicate with that lady but still cannot solve the problem.  The lady asked me to use the links she provided but both shown the same error message.

I just want to change my energy plans but no channel works.  Please help me.

[-Olgi-]

Hi @WingMP,

Thank you for getting in touch. I'm sorry to hear that you're having issues with swapping your plan. 

As we need to go over terms and conditions with you, you would need to contact us via one of our platforms  as per the link you've provided in your message. If Chat or Messenger service are not working, please contact us via 131 245, and we'll be more than happy to go over terms and conditions with you and complete your plan swap.

Thanks,

-Olgi-