I have not gone through that process but my understanding as it stands today if you've been denied continuous coverage for 6 months, states now provide premium coverage for those denied. I believe this will change in 2014 in that no insurance company can deny coverage with a pre-existing condition. This applies to health insurance exchanges in each state.

If you are instead asking about your current health insurer not providing treatment, that would be another issue. In that case I'd sue them in court.