Some people

Some people are not meant to be happy. What ever you do for them, no matter how much efforts you made to make them happy they will still be gloomy and complaining all the time. That class of people is not normal. Actually they are not comfortable with themselves. In state of denial they keep finding faults in others to hide their own dissatisfaction with themselves . They never say a word of appreciation for you or even a thanks when you do good for them but they will curse and complain for the mistakes you have never done. 

The best way to deal with this type of people is not to make a try to make them happy. Be nice to them but don't go overboard. Don't make them your first priority, in either ways they will be complaining and nagging. So, it's better to sort out other important issues instead of wasting time on unachievable  goals which is winning their heart.

We all have this type of people around us in different capacities and positions. Keeping yourself at a safe distance from them is the only way to avoid tension, frustration , annoy and anxiety.