I was sent to collections from waypoint billing from years ago for an account that was paid off. Active Current customer.

I had a past due amount on my old account, I called Comcast years ago and paid it off.  The account was sent to Waypoint Resources for collections and they will not take this off my credit report.    Please help!  I had an 755 credit score last month.  Now it is a 635 and this account is killing me.