There are a number of issues here that aren't addressed in your question but in an effort to make this even nominally useful if it is ever bumped again, I'll give a quick outline:
COBRA is not insurance. COBRA is a regulation that imposed some administrative requirements on employer plans, one of which is to allow ex-employees (who were not terminated for something like embezzling) to remain eligible on the plan for 18-months. This federal requirement is imposed on plans with more than 20 eligible people. Some states extend this requirement via a state regulation, in some cases like California, the administration onus is on the insurer.
Your employer, if over 20 full time employees, probably outsources this administration to a 3rd party. This is the organization that has been receiving your premium payments. This company is the gatekeeper for your eligibility, not your employer and not the insurer. This is the company you most likely have to contact to sort out whatever problem you're having. Most likely, you are not paying premium to an insurer, you are paying an administrator that is remitting payment to your former employer that is paying your premium to the insurer.
Depending on the size of your employer and the structure of the plan, state regulators have no ability to step in. Very large employers don't actually buy "health insurance" for the group which would be regulated by the state, Very large employers "self-fund" their plans and buy an invisible to the participants very high-deductible stop loss coverage to limit their liability. In this situation most employers still use one of the big insurers to administer their plans, so your card could still indicate Aetna, Cigna or the Blues but really the employer is the insurer. Either way, in reality, the state regulator doesn't have the time or resources to step in in your situation anyway.
You need to contact the organization that you have been sending your premium payments to this is probably a third party administrator like Discovery benefits or Conexis/WageWorks. It's very possible your employer had an open enrollment and you had to re-enroll in benefits. If you have a friendly HR staff contact at your former employer, you can start there. That person can be your liaison to the COBRA administrator.