I would like to know, if a player refused to walk back to the referee after being called several times is an expulsion for dissent?

Answer (September 29, 2014):
While it is common practice and tradition that the player do so, I can find no written requirement in the Laws that the player must come to the referee when called or beckoned. However, at least in my opinion, a player who refuses to walk back to the referee is only asking for more trouble than he already has. On the other hand, unless there is a body on the ground or some other good reason for the referee to stand fixed in one spot, there is no excuse for him to remain standing and not walking a few yards himself. Too many referees have a “dictator” complex, rather than understanding that a bit of give and take never hurts in maintaining professional relations during a game.

Dissent is punished for either word or action, and refusing to do what the referee asks could surely be considered as possible dissent. However, unless the player has already been (or is about to be) cautioned, there is no such thing as expulsion for dissent. If the referee has already decided to caution the player for an earlier offense, then a dismissal for the current offense of dissent would he legitimate — and truly caused by the player himself.