My Wallet is where your credit card, debit card or bank information is stored securely so that you're able to easily make payment methods without having to re-enter your details each time.
You can manage your stored payment information by going to Account Settings > Billing and Payments > Payment Methods > Edit
From here, My Wallet, you can Add A Payment Method and Delete any old or expired cards.
When you set up direct debit your bank details or credit card information is automatically debited with the bill amount. Set up a new direct debit with by going to Account Settings > Billing and Payments > Direct Debit > Edit.