An invoice is automatically generated after each of your payments. You can find all of your invoices and payment dates on your Billing page.
Change your billing details
Click on your name at the top right of your home screen and chose 'Org Settings':
Then you'll be able to give us all your billing details:
Remember to click on "change settings".
Change your payment details
Phantombuster only accepts payment by credit card, but you can change the card whenever you want on your Billing page: