Can I claim for the pay during the period of appointment of that post

I have done SAS (Subordinate Accounts Services) which consists of two parts I & II, on qualifying which one becomes eligible for appointment as Section Officer (SAS) with the Finance Deptt. subject to availability of seats. On qualifying Part-I, I was appointed as S.O. as a stop-gap arrangement, on pay scale of my then post which was Clerk and the scale of S.O. was given to me on my qualifying Part-II. Can I claim for the pay of Section Officer during the period of appointment of Section Officer on own pay scale till the qualifying of Part-II and appointed S.O. (SAS)? Pleae quote judgements.