If you are on a discontinued pricing plan and you want to switch to the current Professional plan, these are the steps that you should take:
change the email address of your current account to a variation such as email+old@yourdomain.com.
create a new account with your primary email, which is email@yourdomain.com.
buy the new Professional plan.
transfer your projects from your old account to the new one.
get in touch with us to refund the remaining credit of your old account.
As in the previous model you could have multiple billing accounts per project we cannot transfer the credits automatically, so we'll need to go through this process.
If you have any doubts don't hesitate to be in touch with our support.