why on earth??

can some one pls tell me why on earth Kandy turned against Rusty all od a sudden, i missed that part. didn't rusty help Kandy ????

she in her grief misguidedly thinks rusty responsible for all her misfortune & hence her decision to marry ajit (rusty loves ajit, so if she loses him,then rusty'll feel the same pain as kandy).

Twisted pyschology but she's being mis-guided by mathura who wants rusty out of her life.

Ajit agrees to the marriage coz he feels " well I've done so much for rusty & all she's doing is playing with my emotions".