There is no way to merge two accounts together due to security and privacy concerns. You can contact support to request a refund then file your taxes on your previous account.
https://ttlc.intuit.com/questions/3752786-can-i-merge-my-accounts
https://ffa.lc.intuit.com/questions/1293786-i-received-an-email-about-using-different-turbotax-accounts