Branch transfer 'F' form taxable?

WHAT ARE THE CIRCUMSTANCES WHERE TRANSFER OF GOODS BY PRINCIPAL TO BRANCH FROM ONE STATE TO OTHER BY 'F' FORM IS TAXABLE ?

I HAVE COME ACROSS A CASE WHERE ALL THE REQUIRED DOCUMENTS I.E. LR, DELIVERY CHALLAN ETC. ARE ENCLOSED ALONGWITH F FORM BUT STILL STATE VAT IS APPLIED BY THE DEPARTMENT IN CHHATTISGARH

REFERENCE OF ANY CASES WOULD BE HANDFUL.

THANKS IN ADVANCE