I was contacted by the collectors and said I had some amount due in this hospital. When I called them, it turns out that my insurance didn’t pay for it so it was due. I didnt know if I should trust the collectors so I called my original creditor that was showing on my credit karma account. They had no idea how to handle my situation. I simply just wanted to pay them. Now I don’t know what to do. How do I know if I can trust them so that I can just pay it off and get the collection off of my account?

Edit: It has been a couple of months since they called me. I just found out about this subreddit from my friend. Since it's been a while, will I still be able to negotiate with them to let the amount down?