Are you sure that the charger you just bought is for your phone? Some of the Nokia chargers look alike, but some don't fit as tight as the one you might hace gotten with your phone. If it's loose or does not insert all the way or comes out easily just moving the phone, it's not the right on for your phone.
When I say loose, if you can plug in the plug and with the phone laying on a table, you can pull the plug out, just pulling the phone towards you, it might not be the correct charger.
Did you have the phone with you when you bought the charger? Did the packaging say the charger was for your phone series? If not take it with you next time and ask to plug it in to make sure it works for your phone.
It may also be that the battery is dead, so you might want to see if they have a spare to rule out that the phone is not charging the battery or that the charging hole/slot is not damaged.