Sounds like the ebay seller abandoned your old account when adding the emblem. You’ll need to try & go through steps to reobtain your old Bungie profile (assuming it was w/in the previous 90 days). However, if the new code was entered on your “new” profile, then it is stuck to that new profile & you will then need to determine which profile you wish to keep & only the emblems associated with that Bungie profile will be usable. Also, you should NEVER provide your account/login information to anyone. If that was a legit seller of the emblem, then he/she/they should have just sent you the code to enter on your account instead of using shady methods.