Wrong carriage and packed trains

I was booked on the above train. It is a Voyager and consisted of two five car trains joined together. It only has 2 first class carriages one for each set, however I managed to into the wrong carriage, which I didn’t realise at first. So I had a rather embarrassing conversation with someone who I thought was sat in my seat! However, there were plenty of empty seats in the carriage.

As we approached Crewe, we were informed that there was a fault in one of the train sets, and that it would be detached at Wolverhampton. When we got their it turned out it was the set I was in. So off I got. As may be imagined, the five car set was packed out. Thankfully I was only going as far as Birmingham. However, my short journey from Birmingham to Rugby on a pendolino was also very full.