If you received a refund of the excess amount, plus earnings, by April 18, 2016 then you should not have received a Form 1099-R. According to the IRS:
The only way to correct the mistake, avoid double taxation and potential
plan disqualification is to have the excess amount, plus earnings,
refunded to the employee by the tax-filing deadline for the year in
which the deferrals were made (for example, by April 15, 2007 for excess
deferrals made during calendar-year 2006). In that case, the excess
deferral need only be reported as taxable income for the year the
deferral was made. Refunded earnings attributable to an excess deferral
must also be reported as income; losses attributable to an excess
deferral can reduce reported income in the refund year.
You should contact the 401(k) administrator and have them issue you a corrected 1099-R with No distribution.
