Certain laptop keys not functioning well after formatting

Hello,

I formatted my Samsung laptop by a technician.. after formatting it some keypads stopped working properly.. when I press "K" it brings "2", "L" key brings out "3".. same with some other keys.. the technician said my keyboard is faulty but before he formatted it, it was working properly.. he suggested I change my keyboard.. please what should I do? I'm thinking the fault was from the formatting.. please I need a solution