My brother had the same problem with he's 2012 Nissan sunny (versa) all those you mentioned is been done until I found out that the Temperature selector cable is loose so this means its stocked and its no longer select from heating or cooling so maybe yours is on heating still because the cable is loose it wont go back to cooling ,it doesn't matter what's the Temperature selector showing from outside because the cable is loose and always mixing cold and heat at the same time ,so see if your its not loose for the sunny air conditioning unit was manual I am not sure if your Auto maybe its different , I hope this help . My brother had the same problem with he's 2012 Nissan sunny (versa) all those you mentioned is been done until I found out that the Temperature selector cable is loose so this means its stocked and its no longer select from heating or cooling so maybe yours is on heating still because the cable is loose it wont go back to cooling, it doesn't matter what's the Temperature selector showing from outside because the cable is loose and always mixing cold and heat at the same time, so see if your is not loose for the sunny air conditioning unit was manual I am not sure if your Auto maybe its different , I hope this helps.