Thank you for the affordable coverage, and for 90%...

Thank you for the affordable coverage, and for 90% of the time I do not have any major issues, but I am having problems with the claims department denying claims due to the misconception that I had other insurance coverage during a certain time period. They paid most of the claims but didn't pay some. I have called countless times about this situation and they have promised me that they are handling it, but I have been sent to collections on 2 claims now. Please help!