in your spare time you should be sure to put your face up to their cage so they are used to seeing and smelling you... make sure you talk to them a lot but not in a loud or high voice, as that will scare them
find any excuse to put your hand into their cage, check their food bowl, water bottle, stir their bedding around, move their stuff...
you can also try giving them a treat; such as a very small piece of cheese, moth, mealworm, apple, cooked egg, zucchini, cucumber, plum, banana, strawberry... just hold it in your fingers and place it up to their face... if they like it, they'll take it from you and they'll learn to love human contact because they'll receive treats from your hand (don't feed them treats too often or they will get diarrhea or get fat)
just keep trying to handle them often... don't jump when they bite you because that will make them think that there is something to be frightened of
just keep handling
them... even in spare times... like when you're watching TV or just listening to music or talking with a friend on the phone... they should get used to you eventually
hope this helped... i socialized one 2year-old female gerbil and am currently socializing a 3month-old female gerbil with some success