I commute to work and get a monthly season ticket. Have never bothered to make claims when my trains have been delayed - partly due to laziness and partly because the companies don't really publicise it.
Was recently delayed and got £5 back, which is the cost of a single ticket. I also have two other claims in progress.
I've just found out I can make applications online so it's even easier.
I do it on principal as the cost of public transports in this country is ridiculous for the service you get.
This isn't a dig at the staff, who are generally helpful, but I just wanted to remind everyone to claim if you can.