Verified answer

Contact Adobe Support for your serial number once again or find an suitable keygen from Internet.

that ain't really our problem, we don't aid piracy here - and sharing serial numbers is always piracy regardless of how you look at it.

unsurprisingly, you should actually be contacting the ebay seller about this because if it's a legal copy - i doubt it - it is THEM that should have provided you with a serial number, not us.

Report it with Ebay or take it up with Adobe, other then that theres nothing really we can do legally.

You need to get the serial # from the person who sold it to you, or else demand your money back!!