Servis 60185 was freezing now not cooling

My Servis 60185 larder fridge started to freeze stuff inside so I thought the thermostat was duff (motor just kept running and didn’t click when adjusting). So I have been using it by unplugging when it got cold and plugging it in again when the temp rose (using a thermometer inside). I had difficulty locating a thermostat but now one is coming tomorrow but unfortunately it now seems to not be cooling properly although the compresor motor is running. Not sure what the problem is now as I can’t see it still being a thermostat problem. I would be grateful for any ideas, new larder fridge expensive.