Epic Fail!

Dont know if i am 100% right about ti...but if i am this is one of the biggest Goofs or FAILs i have ever seen on a film!!
During Krishnaswamy's (Kamal Hassan) visit to Kolkata,where he finds his daughter(kaveri) as a prostitute..the actress who portrayed Kaveri is a dark skinned girl...dont know for sure if its make up or not..but that is not the matter here.
Heartbroken krishnaswamy returns to his home with his daughter..
During the next scenes home..the actress is changed!!!
This time the character Kaveri is played by renowned actress Sangita who has acted in a few famous malayalam movies(other south indian languages also)
Here's her wiki page link
http://en.wikipedia.org/wiki/Sangita
Mahanadi is listed in her filmography..
But i am 99% sure that the girl kamal hassan found in kolkata is not played by sangita..
Well this is an epic mistake if am proven right!!
Could someone verify this?