In a fight with CO to get a $150 UG co-pay (miles from a non-elite acct, my $) refunded back to my credit card, as the flight was 3 weeks ago (miles redeposited instantly).

I have two $150 charges from CO, I know one was for a change fee for this same itinerary, the other for the UG co-pay. According to Chase, one charge originated from Roseland, NJ, the other from Houston. The Chase agent thought the Houston one was a reservation charge, but it's a bit confusing as the UG co-pay charge was transacted first. Any experiences on where different charges come from?

Thanks.