Whirlpool fridge freezer persistently doesnt get cold enough

whirlpool fridge freezer arc7610 11.7cf (auto defrost) Fridge and freezer are not cool enough spoiling food. This has been happening persistently for some time. When find there is no motor or auto defrost noise. We have been turning both fridge and freezer off using thermostats and then turning on fridge which starts motor, then reset thermostats. Its then ok for a while but it doesn't get cool enough.