Applicability of vat & cst (gujarat)

A proprietory concern (XYZ) based in ahmedabad has a dealership of a pharmacheutical company (PQR co.) based in south india. XYZ procures order from customers in punjab and harayana. As soon as a order is placed, XYZ intimates PQR co. PQR co. then send the goods to customers at punjab & haryana. XYZ raises invoice which is sent by post to coustomers at punjab & Haryana. Goods does not enter gujarat. 

Question : Is XYZ liable to issue a vatable invoice?