This morning the Oyster reader on the one TVM at my local National Rail station was out of order. Two people were trying to top up their cards but were unable to do so, and apparently not in a position to buy a more expensive paper ticket. What should be done in this situation? (The booking office clerk told them to get on the train and "sort it out at the other end", which I am not sure they could given that they were unable to touch in due to having insufficient credit.)