Business ProfileforSTARS - East Meadow

I am my wits end and really do not know who to reach out to at north well health for answers . I had knee replacement & went to rehap at north-well stars in east meadow . My insurance till May last year was health first ******** but when I turned 65 I went on health first ******** and then picked up my ******** thru ********. I started to received bills from stars in Oct stating I owed almost $300, at that time the billing was be handled by a 3rd party company. I called and told all my info to a young woman who's name was "baby" I was also told not to pay and they would resubmit FYI I did state that billing did not look correct but I was assured this would all be taken care of . Needless to say I still got bills, in fact in December I sent and email to her manger *********************** giving her all my info along with a copy of my ******** card. again I was told not to pay . ** January ***************** billing was switched to rehap direct as per bills. I called their number and once a young lady helped and 2 times a man by the name **** helped I gave them the same info and was assured it was in the system with notes and I should not pay they would get billing to re submit . In Mid April I got a bill from a collection company . I called back billing got **** again and requested a name and telephone of a manger or VP. I was informed he could not give out that info but put in a request to have them call me - a week later no return call. I called stars direct best they could do was send all my info to a Mr ********************* an e-mail .I did get a call back from someone in billing who told me her mgr was too busy to talk to ************ to explain that the reason I was being billed was my ******** has a 20% deduct ale and I needed to pay that amount . Obviously no- one took the time to look at my info I would greatly appreciate any suggestions you might have how to reach someone who can handle this problem along with getting me out of collections . thank you