Credit score surprise

[Farakh Zaman]

Hey everyone. So we've been looking at a property and went to go get prequalified. Both my wife and I have had high (800+) scores all of our lives, but when my credit was pulled we found a nasty surprise. Apparently fly the utilities on one of our properties had sent us a bill to an old address and bc we never knew about it it went to collections.  I just finished paying the people but can anyone give me advice on what happens now? It changed my score from 800 to 600 something bc it sat there in collection for a year and I was never called or notified.  

Very frustrated and not sure if it matters what I do?  Is there any way to resolve it with the credit reporting companies? Or am I stuck with a bad score bc of a $60 bill that got missed?