Goibibo and Vistara Airlines - Neither service provided nor amount refunded

I booked Air Vistara flight on ** Mar **** with travel date on ** Mar **** from Mumbai to new Delhi through goibibo. The PNR number is NFHH*F. On ** Mar **** I received a message from Vistara regarding cancellation of flight due to unoperational reason. I contacted to air Vistara airline and the representative of air Vistara brought out that my flight is cancelled by vistara and you are eligible for full refund and the amount will be credited in your account in fourteen working days and guide me to contact the online agent i.e goibibo. Since last two months I am trying to contact goibibo and Vistara but neither Vistara nor goibibo refunding the amount. When I called to goibibo customer care a automated computerized voice pass the instructions and disconnect the phone. Vistara representative also states that my PNR number is past dated and we are unable refund your amount. i have written on their email addresses and also raise request on goibibo **x* support but all went in vain. It is requested that please pass the order to vistara and goibibo to refund my amount immediately.