Most rail companies are always looking for staff. Everything from Station Supervisors through to Conductors. Salaries vary but are usually around �15k for 'lower grade' platform staff or �20K for supervisors and conductors. If you want to make more money (and could put up with the utter tedium) you could train as a train driver. (Salaries start at around �30k).
Some government agencies (e.g. Job Centres) give 'customer handling experience' priority over qualifications.
Most call-centre work seems to get the 'thumbs down' from its employees but I've known people who find jobs, in those centres which only handle incoming calls, to be reasonably satisfying.
If you've been working in a customer-facing environment what about 'Reception' work? (In an office or hotel, perhaps?)
Chris