I would first talk with your accountant to see which is the best method to pursue: (1) Get refunds on the taxes you paid; or (2) take the money out on an after tax basis. Depending on what your accountant says, then you might want to talk to a tax attorney about (1) above. I am assuming that the program was a Code Section 457(b) plan. You can go back and get refunds for years that are still open (there is a three year statute of limitations unless the amounts exceed 25% of your taxable income and then it is a six year statute). I suggest you get a tax attorney, because there is a relatively obscure set of rules that allow taxpayers the ability to open closed years because the inclusion or exclusion of tax in a previous year will impact the taxation of the item in a later tax year.
First, figure out if it makes sense to take the funds out without having the distributions be taxed. If that does not make economic sense, get a tax attorney.
I also note that you may have an action against your former employer for negligently reporting your income to the state and federal government.