Samsung fridge not cooling or freezing

My fridge went hot this weekend…I took off back panel exhaust fan is working…compressor is hot…took off back panel in freezer fan is working…there is a clicking sound every few minutes like it is suppose to make something work so it clicks instead of making it cool? I have looked online done everything from unplugging and back…nothing resetting front panel…nothing just clicks…I have had a icing under the back panel in freezer since I bought it new in 2009 so I assume the defrost has never worked as I have had to defrost every month since purchase…repair put me off til the 1 yr warranty was up and then said I wasn’t covered any longer…so I know that the problem now isn’t just the defrost isn’t working but something else that the thermastat is trying to turn on that is broke,is it anything obvious because I can not afford a service call and a bunch of money to repair I just need to know what part is broke? thank you and God Bless
Carol