fridge freezer not getting cold?

i have a frigidaire fridge freezer

model fre2422a

its 3 years old and in the last two days
its been getting warmer and warmer.

the light in the fridge lights up when the door is opened and the temperature setting nob is set between 3 and 4.

the motor is working to the extent that is hot
to touch and it buzzes but neither the fridge or the freezer gets cold.

any ideas.