In simple terms, can you change an advance ticket at any mainline station as long as it wasn't purchased online. As I have reported in this thread http://www.railforums.co.uk/showthread.php?t=34807, I was told by my local station (where I had bought the ticket and then wanted to change it), that I had to change my ticket there since it was the point of purchase. Since they are saying it is not possible to change the ticket when it quite clearly is, will I be able to try elsewhere?