Is it correct question?

[ramanji]

Why did you change calling me from Chinnu to Bhuji?

or
Why did you call me Bhuji instead of Chinnu?

[2006]

Why did you change from calling me Chinnu to calling me Bhuji?

or
Why did you call me Bhuji instead of Chinnu?

The meanings of the two sentences are not the same. The first one, with "change", means that in the past you used to call me Chinnu, but now you call me Bhuji.

The second sentence refers to one instance (or one short period of time) that you called me Bhuji instead of Chinnu, and suggests that it only happened once (or over one short period of time).