Unexpected excess assets from plan term

[Medusa]

Late last year, we terminated one of the sponsor's two defined benefit plans. The plan had excess assets that were allocated to participants. All the distributions occurred before 12/31 and everyone was pretty much thinking that 2000 would be the last 5500.

Now the insurance company who provided the annuities has come forward and stated that they made an $11,000 error on the annuity purchase. They charged $11,000 too much and want to send a check back to the plan. Can anyone think of any way to deal with this without having to do another 5500? Unfortunately there are no plan expenses to deal with, these were all paid by the plan before terminating it.

There is probably not a good answer here but I feel obliged to ask. Thanks in advance for any responses.