While I agree that the current storyline is really testing the viewers' patience, it would be wrong to say that it is unrealistic. Sibling rivalry is fairly common, in fact I would go to say that stuff like this happens all the time between friends too. I know because I have had stuff like this happen to me in personal life where a friend of mine always tried to prove that she was better than me in everything whether it was school, dance, extracurriculars, whatever. Our relationship got to a point where I was so sick of listening to her that we just stopped talking all together. Now that I look back on it, I stop to wonder if things would have been different if I tried to talk to her about it instead of just walking away, but then again, who can change the past so its better to move on and be happy with where you are and where you are going.
I am sick of seeing all this war/fighting between Rachna and Gunjan but if in the end the CVs resolve the matter in a logical way with Rachna becoming more mature and understanding and Gunjan also realizing that she does not always need to be mahaan for Rachna's sake then I think that these torturous weeks of watching fighting will be well worth it!