It said online chat was not available so I rang them this morning and got through to a South African call centre who sorted the issue in 2 minutes. I've only took this out so I can port my number away from Vodafone, when the 5 X data ends I'll take out a new contract with Vodafone and port back.
Go on the help page then contact us. Wait for the chat to pop up
I have had exactly this issue, I rang customer services and got a recorded message saying they were not taking calls and directed me to the website.
Just note that you will most likely need to speak with customer services for the £10 free credit. You text FREE10 to 21500 for the promo but it says ineligible for the offer. But they do apply £5 automatically after registering. So will need to make a CS call. The 5x data applies a few days after topping up the £10 so be patient
Fingers crossed that you find something before the end of the current contract.