No bro. Your calculation is giving the validity till 26-Mar. Check the below calculation as per your output.
As per you the remaining validity would be 76 days as on 09-Jan-14 after activating DVR. Excel says the date after 76 days from 09-Jan is 26-Mar (not 17-Mar which is the correct date as per D2H website and my excel).
18.7397 + .9863 = 19.7260
dbr + dvr = new dbr
74.9588 which shud be the balance of remaining 4 days (21-17 march)
u took a dvr so ur validity is 4 days less which costs u around 74.9588
now divide 74.9588/.9863 =76 days
To do this, you have to input Rs.60 under Debit column against 28-Jan since it is one time payment.
Don't give Add-On amount Rs.60 under Add-on column, since it is not a daily payment for the next one month. Give the amount after one month (after lock-in period).
By doing this, Rs.60 will be deducted from your balance on 28-Jan and so the next recharge date will be adjusted.
Next day onwards, the DBR will be the same which is only for base pack and not for add-on. So there won't be any change in next recharge date.
Try this once in the Excel and let me know what you are getting.
For the case of my DVR add-on, since it is free for 3 months, they credited Rs.90 and then deducting Rs.30 per month via DBR.
So, I mentioned Rs.90 as credit which will increase the balance.
Since the DVR amount of Rs.30 is being deducted as DBR, I added it under Add-on, so that it will be included in DBR calculation. In that case, the DBR specific to add-on will be varying month to month. This is how D2H is doing.