How can I change my account from a PRO user to a BASIC user?

There is no way to downgrade your account from PRO to BASIC.
You will need to cancel your existing account and sign up again...this time as a Basic.  

We suggest you contact help@printgenie.io for help through this process, as your  phone # cannot be the ones you used for your BASIC account.  

We will need to remove them, so you can use them again for your new PRO account.