bill is on the 1 of each month. for you, your 1st bill will be on 1 Feb.

on this bill, got few charges:

1) prorated monthly fee from 8 Jan to 31 Jan. This is your current month charges since activation on 8 Jan until 31 Jan.
2) advance monthly fee from 1 Feb to 28 Feb. Basically you are charged 1 month in advance first.
3) repeat same thing the #webenow discount. got prorated and advance as well.
4) additional charges, such as roaming or idd call charge, which are not covered under this unlimited thingy.

what you going to pay by 22 Feb (this is payment due date, which is 21 days after bill date on 1 Feb bill) is.....

advance payment that you paid during registration = RM106 minus all the charges above.
FYI, your plan will remain perpetually RM79 monthly from 1 Mar onwards (cuz 1 Feb bill got proration, that is why higher).