I just realized that I didn't include a 1099 form from last year (2015) & I was owed $1k. What can I do?

I withdrew my 401k early to help me pay for grad school. I received 5k on December 22, 2015. I was told that I was eligible to receive money back on taxes (around 1k) because I was using it to further my education. When I filed my taxes in January 2016, the tax preparer told me that there was nothing I could do to receive that money back until 2017. Now, looking at my 1099, the date on it is 2015 & I never got that money back. What can I do?
Carl
Level 15

Retirement tax questions

Take that 1099-R to the preparer who provided you incorrect information, and insist they file an amended 2015 tax return, on your behalf, at no charge, since they gave you flat out wrong information in the first place.