samsung fridge/frezer Model SRS2028CSS?

Can you give me advise I have the above samsung fridge/freezer, the control digital freezer light keeps flashing then the fridge defrosts and the fridge stops working also after approx 2 - 3 hours the flashing stops the freezer and fridge start to work again then after several hours the above proceedure repeats and the freezer starts to defrost again and fridge stops working, I have had an independant freezer engineer who was not sure what the problem is !!!!! he advised me to contact a samsung engineer , Can you Help em Please