Each time my mother and sister confuse my name with my sister son's name it makes me dislike them.
What do you hate about this?
They should know better by now peoples proper names.
It is wrong to confuse peoples names on purpose. If they forget you should tell them and get them to use the right name.
They can just ask instead of calling the wrong person.
You're right, and you should explain to them how this makes you feel. They may have a reason for accidentally doing so and understanding them may make you less upset about it.