Pandora does not use account numbers they use your e-mail as your account number are you trying to login or are you attemping something else?https://help.pandora.com/customer/portal/articles/1468387-change-your-account-settings#4
"Listening on Multiple PlatformsPandora accounts follow the email address, not the device. You can sign into the same Pandora account on any computer or supported device, as long as you use the same email address and Pandora password.This applies to both free and paid Pandora accounts."
let me know if this helps
It is $54.89 yearly and 4.99 monthly according to their website to see this login through pandora.com click on your e-mail address on top right corner then select settings then on the next window on the left side select upgrade. I really hope you did not sign up through a fake pandora website. Does your bank account transaction history show pandora as the name. I would send them another e-mail and make sure you paid them not someone else. Let me know if this helps.