Does it make any noise at all? If not check your starter relay. Find one of the other relays with a similar rating (usually 40-50amps) and swap it, if it starts you know your relay was bad. A voltage drop test can also tell you if you have a bad starter.
Search Mitsubishi Galant Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Mitsubishi Galant Experts