As Engineer Spike said above, the railroad isn't what it used to be. Nowadays due to "equal opportunity" they hire just about anybody, but tend to chose "minorities" and women to meet quotas. Here at Amtrak they're more likely to take a retail store employee over a freight railroader basing their decision on customer service. I understand that trainmen will be dealing with the passengers, but far too often those chosen can't handle all that can go into the job when the * hits the fan.
If you're in New England and you want to work for the railroad, apply to Amtrak or MBTA Commuter Rail, or Metro-North.....depending on where in NE you are. CSXT did me well during the beginning of my career and I never saw myself going to passenger service. However, once I saw how things were going, and the future not looking like it would turn around, I came to Amtrak and started all over as a new man towards the very bottom of the roster. That was the best decision I could've made.
By the way, not dressing up more was probably their first strike against you when you went to interview with CSXT. You have to realize that usually these carriers have hundreds of applicants for each individual position that is posted. You need to try to stand out, without going overboard. Unfortunately for you, you stood out by not buying a dress shirt and tie for the interview. Sometimes ya have to spend a little money to make money. If you get another interview, do yourself a favor and got to Marshalls or TJ Maxx etc and spend $20/30 on a pair of dress slacks, and another $20 or $30 on a dress shirt/tie combo.