My GE Monogram cools slowly. How can I fix?

I have a side by side GE Monogram Refrigerator. We are in middle of remodeling and moved the refrigerator to the garage and it is connected to an extension cord. Our temperatures were showing high: Freezer 37 Fridge 60. We reset temperatures to move Freezer to 0 and Fridge to 37. It took week and a half for it to finally get to those temperatures. Then a week later the temperatures rose again. We are thinking maybe because someone hit the extension cord and the fridge lost power. Now we are back with this problem again. Do you think something is wrong with the refrigerator, or is it because we did not have continuous power to the fridge? Any HELP would be appreciated. THANKS