Paid for item outside of my account - need to return
I ordered an item from a website and paid via my credit card through Paypal. But rather than logging into my paypal account, evidently it created a one-time temporary account.
Now I need to return the item and request my money back (dispute the transaction) because the wrong item was sent. However without the correct login, I don't know how to do this. I have the transaction ID, but no way to dispute the transaction without a login.
I do have a regular Paypal account, but I don't know how to connect this one transaction to my regular account.