What counts in the rail industry, as in most businesses, is some prior experience in an area related to the career you are aiming for. If you have had previous customer related work then you may stand a reasonable chance of getting a platform job somewhere, which could be just the thing for you!
From my own experience I suggest that studying a University degree that will lead you towards gaining greater knowledge of your preferred sector of the rail industry, but it's a matter of personal preference.
I am currently studying for a Transport Management degree. It's only a small course, so has a high standard of teaching, and covers not only transport based subjects (global shipping regulations, multimodal operations, transport planning), but also business management, statistics and accounting which can all be important skills. There are also logistics course if your interests are more centered towards moving freight.
Taking up a uni degree doesn't just increase academic skills, it allows you to gain that all important work experience in the transport industry by the time you graduate: When I completed my A-levels, I had no work experience in transport, and I have now worked for two big players in both the public transport and logistics sectors and really boosted my CV and experience to a level beyond many of my peers. Some courses also offer a placement year, like mine does, which is a year earning a proper wage doing a proper job in the transport industry before you graduate. The big names in transport and logitsics offer places to certain universities for students to work for them.
Univeristies that offer the Transport Management course, and I know for a fact are offered many good placement opportunities, are Huddersfield (that'll be closest to you), Aston (Birmingham), Loughborough and Bristol.
There are also degrees in engineering and construction, and of course the Network Rail apprenticeships if you want a more hands on approach and would prefer to get straight into work.