I gave a letter to BSNL broadband person in my exchange for change of plan from 500combo to 600combo on 29th nov and got acknowledgement from them. In bsnl selfcare page it still shows up as 500c plan even now. how long does it take for them to change plans? asking cause data limit in 600c is 2.5GB compared to 1.5gb in 500c and i dont want to be charged extra at end of month, thinking plan got changed but the person did not feel like changing it.