I don't want to logout but I want to delete but how

there are many applications which we download each day and then after using for a couple of times the offers of that application are no good enough 2 use it and these applications do not have a delete button but they have a logout button my question is how do I get my self deleted out of their system is it possible without much effort are then I have to write a letter to some head of the department who is dealing with these applications in India which is that organisation can you help me I will really really be interestedto know this is it some government for a simple 12V query is it possible to delete BigBasket account and not just logout