On Monday the 14th May, me and FishQuinn where out and found that 1S51 Plymouth-Glasgow was running late and caught an XC 170 from Derby to Tamworth. We asked the Guard on the 170 if we could buy a ticket on the train he said yes and was all fine. We got of at Tamworth and waited for the HST. And the guard on the HST was looking at FishQuinn's ticket as I was in the other vestibule at the time he came round. He then asked who is the railcard (F&F) holder who was me and claimed that there needed to be a adult as I had a 16-25 railcard underneath. He lost that one then claimed that you have an invalid railcard but was bought before FishQuinn turned 16 so is valid until it runs out. He also claimed the FishQuinn needed ID but he is 16 so he doesn't need it and lost that one too. And through all that forgot to check the ticket. We bought a Derby- Tamworth return.