Please cite the authority for that very specific instruction. And please confirm what your role is in the company.
The fact that there's been forum members join for doing similar things like that and are now facing charges of fraud! The very reason the thread you have just posted in was required!
I'm surprised you haven't taken the time to read the appropriate thread yourself.
How any reasonable person thinks a train being cancelled at 17:00, with another half an hour later, allows them to simply waltz up and travel 2 hours or some other time of their choosing, later, by their own free will AND claim compensation baffles me beyond belief. It's illogical, and it would be to many of my professional, learned colleagues. How about travelling at 22:00 after a few pints too? The next morning perhaps?
At the extreme, are you saying it's acceptable for a train at 06:30 am to be cancelled, with another one 15 mins behind, but you decide to stay in bed after checking online, and travel 12 hours later at 18:30, and still claim 15 mins worth of compensation? Do you believe a rule allows this?
As usual, you and several others are making the error that I am condoning what the operators are doing, or some are doing. I have absolutely no view either way, it makes no difference to me! But some of you are totally blinded by your enthusiasm for the rail industry, and a love of rigid terms and conditions, and consumer rights- which I'm sure you are largely quite correct about. But most people who matter in resolving these issues, including the judiciary, police and investigators, simply do not share your enthusiasm or beliefs, and default to their own perceptive test in reasonableness, without any real legal basis. That is the reality, which is why private (and some public) businesses can act however they like without real consequences.
The test in crime should be beyond reasonable doubt. In reality, for summary offences it is simply not. That is our justice system, and even if you did get found not guilty, you're not usually entitled to anything for your troubles.