I would stick with him for 1 or 2 more games. If he fails to improve as a bowler in that time, then he has to go sadly. Having said that, if they played him as an all-rounder at 6/7 then I'd keep him till the end of the next series and then reassess.
Jadeja should be given at least 2 more games too, if not the whole series to show what he is capable of.
I'd go with jadeja at 6/7 and ashwin at 7/8 depending on the wicket keeper's position