When to quit a Mutual Fund?

#1
In mid 2011, I had Rs 30000/- at my disposal, & I put it in DSP BlackRock Small and Mid Cap Fund (G) one time. (I consulted its summary on a website, it was recommended, & I chose on my own)
I needed some money end of 2014, & I visited it. My fund value was 56000/- approx, & I took what I needed.
At the same time I saw that the same website is recommending to switch to another fund in the same category.
I do not understand the theory of investing, & hence I am asking for help.
1. My idea of my own ROI is like this : absolute growth : rs 26000/-. Total % growth : 86.67% --> approx annual returns over 4 years : 21.6%, which is satisfactory for me.
I know this is not inflation-adjusted, & basically very childish ... but, is my thinking FLAWED?
2. What is meant by CRISIL rank 5? & what is meant by not ranked?
3. What are the indicators that a fund is performing so poorly that it is definite time to quit?
Thanks in advance!