BSNL Plan Change Causes Extra Bill charges?

[BSNL_User01]

In April 9, I changed my BSNL Fiber Value plan [704533] - rs.799 to Super Premium Plus Plan [704861] - Rs.999. In the April Bill, It charged as Rs. 2495. I don't the reason for it When i checked the bill details it mentioned as below.

Monthly Charges
Description & HSN / SAC Code Start Date End Date Amount(Rs.)
Bharat Fiber BB - Fixed Monthly Charge-998412 01/05/2023 31/05/2023 999.00
Bharat Fiber BB - Fixed Monthly Charge-998412 09/04/2023 30/04/2023 732.60
Bharat Fiber BB - Fixed Monthly Charge-998412 01/04/2023 08/04/2023 213.07
Total 1,944.67

One Time Charges
Description Date Amont(Rs.)
BB - Plan Deposit-998412 09/04/2023 200.00
Total 200.00

GST - 350
Overall Total - 2494.71

Anyone explain it?. Is the next month [May 2023] will be paid as advance for adjustment.?

 

[sniper]

I was told today by a BSNL customer care executive that they are charging EVERY bsnl subscriber a one month advance bill in the month of May & that in the next month, to adjust, BSNL will NOT be issuing any bill. So far I've come across a few people who have reported this on this forum BUT all of them have changed their plans in the month of April (including me). So, either BSNL is charging a one-month rental in advance to those customers who have changed their plan in the previous month OR it's happening for everyone. Will request other BSNL users to confirm if they too have been charged a one-month advance bill or not.