Can I save energy costs by turning off the refrigerator for 1-2 hours every day?
You'd need to run an experiment to confirm this, but I think it would be a false economy.

Even though the fridge is well insulated it will warm up by some amount. Then when it's switched on again the cooling would have to work harder/for longer to bring the temperature back down again probably using the same (if not more) energy in the process.

Let the thermostat do it's job and keep the fridge using a little energy over the 24 hours to keep the temperature constant.

You'll save more energy by opening the fridge less often during the day.