Change of name

Hello there, I have booked train tickets online, and my travelling partners are in another country, so I have booked with the information they gave me online. Now it seems after asking them several times if they had a middle name on their passports, and them saying no, I now find they have, so the tickets and their passports won't match, as their middle name is missing. What should I do? Any suggestions? Any help much appreciated thankyou, Barry