So sorry if you were not aware of this--but using money from your 401K purchase a home is not an exception to the early withdrawal penalty. That only works with an IRA. If you have already taken the money out of a 401k you will owe the 10% early withdrawal penalty and the ordinary income tax on the distribution you took. You will receive a 1099R in January that you will need to enter on your 2017 tax return.
If you just took it out maybe you could put it back. You will have to add back in and replace any withholding they took out. Ask the plan. Did you take a distribution or just a loan?
OP has asked same question several times, and it has been answered.
Ironically one of those answers given 6 months ago was from ME! OP cannot say they were not informed they are not exempt from the early withdrawal penalty. @carla4chris2015 You have asked about this several times and you have been advised each time that you will be subject to the early withdrawal penalty for a 401k. Are the responses going to the correct email address for you?