The Court gave your spouse 1/2 of the account and that always includes earnings until it is paid to your ex. If you have contributed since the division, you'll get credit for the new money and the earnings associated with the new money.
Compensation is one of the few areas where employers get to choose what they pay or what they do not pay. while excluding part-timers was clearly not a popular move, employers have every right to determine what their employees are paid.
Legally, they do not have to distribute to you until retirement. They most likely, however, have many exceptions. Be nice and do what they ask and you will most likely get your money.
Once you are enrolled in your ex's retirement plan you remain in until the next open enrollment. Where a life event (marriage, divorce, birth of a child, change of job) occurs your ex may drop you. Check to make sure you are on the dental plan and then get the work done. Your ultimate divorce settlement will spell out how long you have to be covered.
Your COBRA rights terminate once you are eligible and then accept coverage with a new employer. Be careful as you may not be able to get the new employer's health care unless you do so at the time of your hire until the next open enrollment date.
Put in a claim for benefits. If it was your employer's error, they are responsible for the loss. They cannot retaliate (without consequences), but you must establish that it was in fact their error.
You may think they did not give you notice (usually done during open enrollment), but they most likely did and you do not recall. If they did not provide notice of the increase, you might still be stuck because you always have the right to opt in or opt out. Quite often, the cost of benefits goes up and employers do not always want to pick up the extra cost. You may also think you will get the same coverage cheaper elsewhere, but be very careful. The ObamaCare website often quotes rates that take into account the tax credit which makes the premiums look like they are less. If your employer has provided "affordable" coverage for you, you do not qualify for the tax credit.
Vesting percentages do not drop under ERISA. You were fully vested and it looks like the 401(k) plan had a partial termination at the least. Make a claim for the amount forfeited.
You are fighting a battle with lazy employees who do not want to hassle paying you a small amount. All State and local retirement funds have two very important sets of provisions: (1) Penalties for not doing something required to be done; and (2) attorney's fees provisions. You have already started the ball rolling by completing what they requested and continually checking to get a status. Make sure you document every phone call and letter or e-mail. Eventually you will get someone to respond, but, if you don't, you have a great class action suit that will make it worth some attorney's while because of the attorney's fees. Keep up the contact until it gets rediculous (it has been two years, maybe keep trying for another year) and then try to find a class action attorney to take up your case. There will come a point where the Court will throw the book at the employer.
If the QDRO was properly prepared, your ex-spouses benefit should be based upon the time between your marriage and the separation. All future accruals should be your separate property.