If I were you, I would write to US Customer Service and simply request the difference in miles for the coach vs. first class ticket since you were, in essence, downgraded. I would expect that you would receive such a difference, at least for the one-way, plus perhaps some sort of token for the inconvenience (I would cite the delay/cancellation of the earlier flight and the hassle as well). This was not a revenue ticket, so asking for cash will likely get you turned down. You paid with miles, so your credit should be in miles. If US is nice, they'll give you the miles, plus maybe a coupon of some sort for the added hassle.

As for the oversale of F, most airlines, including CO, do not do this (you wouldn't want to bump a high-paying passenger). I've only seen it once (on CO when a 757 was downgraded to a 737 at the last minute, and they had to un-upgrade some Elites including myself ). Typically when a flight is that close to departure, an airline doing a 240 needs to call to the other airline (US --> CO in this case) and ask first if they will release the seats. I believe the rule on this is if the flight is within 4 hours of departure, which it was in your case. Just like you can't logon to a travel website and buy a ticket for a flight 2 hours before departure, another airline cannot move someone 2 hours before departure without asking first. This rule is there because within 4 hours, the flight is under airport control, and it is a known fact that the reservation system is unreliable in that timeframe. Every time I've been bumped to another carrier, the agent first picks up the phone before agreeing to rebook me. Clearly this was not done, probably because US was too busy rebooking 100 passengers. Mention that in your letter and state that had US called and learned there was no F availability, they could have selected another carrier with F availabilty.

If you want to leverage this to get something out of it, you could also write to CO and explain your dissatisfaction that you did not get into F as you were ticketed for F. You may want to concoct a story about how you live in the IAH area and travel to EWR frequently and were considering switching airlines because of CO's service and US's impending financial doom. Do NOT mention that this was an award ticket.

Regardless of whether or not you write CO Customer Service, you should contact OnePass with your ticket info and try to get the miles for your flight. The fact that this was an award ticket may have gotten lost, so you may get CO miles if you want them.