Contingent payment debt instrument - Structured CDs

I had a structured certificate of deposit (FDIC insured) tied to the performance of a market index. The payout of the CD was a "point to point" structure and had no interest payments during the 4 year term. For the past 4 years I was  paying original issue discount interest (phantom interest) from form 1099-OID (about $2000 total for the 4 years total.)

It turns out that the market index declined over the 4 year period. So I simply received the principle back ($25,000) with no profit.

There is a 1099-B showing $25,000 for both basis and proceeds.

Since I didn't make any money I need to know how to "take back" that ~$2000 as a loss. I've been reading Pub 1212, but it is unclear on the exact way to report.

Any suggestions?