Medical collection on an insurance dispute. Remove clean delete

I have a medical collection due to an insurance dispute and would like some coaching to get it removed from my report. I am getting divorced and not receiving all the mail. My husband's insurance changed processing agents and was requesting documentation of additional coverage (which I didn't have) before they paid my claim. I was unaware of their request due to my husband's lack of notification. When I discovered the charge was on my report I called the doctor's office and paid the bill in full. Now I find out that I over paid because they were a PPO for our plan. The insurance company is paying the doctor directly and now I have to fight them to receive the overage plus they won't help me to remove it form my credit report. I haven't contacted the collection company yet and would like to know which is the best direction to go to have this issue resolved.
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the ppo would be liable for the late payments
thats why to doctor bill doesnt want to help
all they see is you were late and thats all
maybe the ppo could help

but if you already paid there is no incentive to get the doctor to help now that they have the money in hand

so i would haggle with the ppo and see wht relief you can get
and of course the my husband thing will always be trouble
until
you are totally removed from all loans, insurance and anything credit