M.P.
I tell my 4yr old daughter "daddys busy" or "he's working" because if you tell her the truth she will be upset with you for saying bad things about her daddy. Its sad that he doesn't call her and even sadder that he doesn't let you call her because he doesn't wanna be a good parent he wants to make you look bad in her eyes as well. Don't stress too much she is almost to the age where she will be able to see what is really going on and have her own opinion of him. Good luck