said they were calling from my college. they knew my college, but the phone number isn't a local area code where my college is located.

I luckily didn't pick up the phone for  this call.  This person is still at it.  Knew my college and everything.  I was immediately suspicious of it though seeing as I had given my school my information when I had gone in for a sinus infection.  She gave me a number to call and I did, just to see what it was and it turned out to be a prayer line.  Still an active scam, folks.

They are a legitimate company that your school most likely signed a contract with for health services. They aren't out to get you and the reason the phone number is not local is because they are located out in Texas but they are trying to rob you, just to get the money you owe for past visits.