If you book for a cylinder they never delivery the same on the said date.Any how they will take at least 15 days. Even they are not picking up the phone at all. Minimum if try for continuously, there may be a chance. If they pick up the phones means, you should say thank God. But the thing is they will assure as deliver the cylinder by today or tomorrow because of no stock. I had same case for the last 3 times . So I have decided to go for other than HP.