FMLA Insurance Question

I pay all my premiums for Health Insurance at my job. I was told to contact HR in regards to making payments to keep my Insurance up and running during FMLA. Under advice from my Psychiatrist, I am to stay home and de-stress and not return to my work place until my next appt with the Psychiatrist.
I have called numerous times to my local HR, to my Corporate HR and to the benefits number I was given to make arrangements for paying my Insurance. I have also sent 2 certified letters to my local HR office and Corporate HR office. Still no response or call to inform me how to pay Insurance.
I have also called my Insurance company to see if they could intervene on my behalf, but they can only refer me back to my HR Dept.
What do I do now? I don't wish to default on my insurance, but I have no communication with HR.

 

Thanks for responding CBG. We have an off shore payroll department where my insurance gets pulled from out of my paycheck twice a month.
I was told by my HR that they would give me the information on how to pay the insurance and would contact me. That was 3 weeks ago. Based on my understanding from what I was told we don't pay HR directly.
If HR does not respond to my calls or letters and I default on my insurance they can deny my FMLA, correct? If that is the case can they can fire me for missing work not under FMLA, when I have proof of trying to make payments?
It seems they are intentionally antagonizing me by not returning calls or communicating in any way. Any other advise I may go about, since I have already sent return reciept requested letters?