Welcome to the Community!
We have an article that will guide you on how to update and pay your bill online.
Check this link:
Hi @lemontree63, you may refer to this link to pay your bill online : Update Credit Card or Direct Debit payment details or Re-try a Failed Payment securely online
Should you need further assistance, feel free to PM us your TPG customer ID, username and complete address so we can pull up the account and help with your concern.
To send a PM, please refer to this link: How do I private message (PM) in the community