That really does not matter at all. Your ticket IS valid as many people have explained to you. People on this forum has used far questionable tickets to travel than yours and have lived to tell the tale. Don't worry your journey using that ticket will be fine. We understand you are feeling nervous although you have nothing to worry about. Staff get things wrong sometimes and you should take what you are told with a pinch of salt as what they say is not gospel. Nobody knows everything but some no nothing. It might be a good idea to complain about the staff members you spoke to as they should not be giving out advice that is wrong.