Your question involves several legal issues and I would encourage you to consult with an attorney in your area. There are several issues to consider. First as to your life insurance, it appears that this is a group benefit plan made available through your employer. As such, it will be controlled by Federal law under ERISA (Employee Retirement Income Security Act) which governs all employer provided benefit programs. The wording of the plan language re: "disability" and "qualifying period" for premium continuation need to be reviewed to determine if the Insurance company's action were in violation of the plan.
Also, if your employer is subject to the Family Medical Leave Act (FMLA) they may have been required to hold your position and not terminate you. This might also re-open the premium rate guarantee.
You indicate that you will be disabled for quite some time to come. If the disability is going to continue for over a year, you may qualify for Social Security Disability benefits.
Finally, you do not indicate what caused your "disability" but if it was related to employment or work-related, you may have workers compensation benefits available. Or, if the disability was caused by the negligence of a third-party you may have a liability claim for damages against the third party.
All of these various issues or potential issues should be discussed with an attorney in your area. You have a complex situation involving several different areas of law. I am not licensed in your State so I can not provide anything more specific to this response.
In addition to the above answer, whenever anyone has a delayed or a denied life insurance claim, they should retain a life insurance lawyer by googling "life insurance lawyer" ...here, I did it for you... www.InsuranceClaimLawFirm.com
John Lassen 1-877-252-4630