Is it possible to switch from a personal plan to a student plan without cancelling the personal plan?

​@Lívia Araújo thank you for posting. I can confirm you are already on our discounted plan. You will want to check with your educational institution to see if they offer their own plan, which is often at a better value and with more compatibility than the ones offered directly through Adobe.

I do see that you currently owe us money for your current commitment, ​@Lívia Araújo . Please see https://helpx.adobe.com/account/individual/billing-and-payments/payment-and-billing-issues/retry-failed-or-missed-payment.html for information on how to correct your account. Your account must be in good standing to manage your plan or end your commitment to Adobe.

you have to first verify your student credentails, https://helpx.adobe.com/account/individual/subscriptions-and-plans/renewals-and-cancellations/renew-adobe-account-plan-student-and-teacher-discount.html

As far as I know, you may not have 2 plans, but you SHOULD be able to change without a fee

Change plan https://helpx.adobe.com/manage-account/using/change-plan.html