Silver Ring Thing and School night trouble

Well He went to The Silver Ring Thing that was a good thing the problem was that he was supposed to be home no later then 9:45 which was pushing it on a school night anyway and this was a church event so I said okay he can go he needs to. Well Dad took off to pick him up and about 10 min after he has left the teen calls and says mom we are just leaving the concert okay this is when he was supposed to be home....HELLO.....it is a school night and now this so now instead of being home at 9:45 he will be home more like 10:30 which is past curfew and bedtime yes he still has a bed time not to mention he had a light supper to hold him over till he got home needless to say dad is gone and I have no way of getting a hold of him to tell him he will not be there till later not a good thing.... and now Keaton has to stay up to eat and all of the before bed madness great so about 11:30 in bed gonna be tired tomorrow I am a bit upset with the church cause well I was told one thing and last minute it changed and that just does not fly with me so now what to do about this situation grown ups should have been better prepared and knowledgeable not to mention responsible....