All I want to do is pay to update my smarty sim

https://help.smarty.co.uk/en/articles/952717-updating-your-payment-method

Hi there,

If you require assistance making a payment or changing your payment mothod, please raise a webchat with the SMARTY 

Customer Support Team, they can assist you further, they are online 7 days a week between 8am-8pm and can be contacted directly here https://smarty.co.uk/contact

Remember to ask to 'talk to a PERSON', rather than the bot.

Have a great day! -Adrian.