Indian Oil Corporation — Change of contact number in gas booking form

I am a consumer of indane gas and my connection no. is 9155 with Zhirka Indane, but at the time of filling the form, the contact number was furnished as [protected] in place of [protected]. However the contact number [protected] is already connected with the gas coonection of my son Raj Kumar Gupta bears No. 12757 and now very much problem to book the gas refil. Now i want to change my contact No. in the form as [protected] in place of [protected]