A dispute for an unauthorised transaction is telling paypal that your account was hacked and used without your consent to make that transaction. Paypal would check IP addresses and devices and close the dispute if it was you that made the transaction.
You are only allowed 1 dispute per transaction so the only way you can get a second dispute opened is to contact Paypal (when and if you can) and see if they will open a second dispute for you. They may decline citing policies but if you say what happened then they might open a second dispute for you.
If not then if you funded your paypal payment via a credit card then consider contacting your card issuer and see if they will help you with a chargeback?
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