Wanted-Catalytic converter for a 1999 2.7L

Hi, Im looking for a Catalytic converter for a 1999 2.7L. I bought the wrong one new on eBay and it was for a 2.4. They are two different sizes in length. Cannot return.

 

It's E-Bay, why can't you return it? Heck, you can return a brick instead of a radio and E-Bay would do it.

Was it a used one?

Can you have a piece of exhaust made/customized to make it work or does it have to pass visual inspection?

 

It was new in box via a private seller. The part number was on it. If you look up on google for the part number for a 2.7L it comes up as walker 16360. I called walker and the rep. said no, its for a 2.4. Its like 12.5 inches. The one I need is different number and 17.6 inches.

 

I thought about getting a coupling piece but I don't think I want to put the effort into it.lol.
If someone wants to buy the walker 16360 please let me know. Its new for a 2.4L.