Q: I have a valid subscription, but now I want to upgrade to Premium / Pro / Elite Plan. Or I want to downgrade to Basic? What should I do?
A: You can covert your current plan’s remaining data and days to credit and resubscribe another plan using this credit. This can be done here: https://support.simplelink.site/user/code
User Center => Payments => Subscription Record.
On the Payment page, you can scroll down to the bottom of the page, and there you can find a Subscription Record tab and at the end of tab, there is a button to convert your current plan to credit.
Once you have converted, you can go subscribe another plan with the credit you have.