It shows that the balance of your last bill was 456.2 yuan. If you didn't spend the same 405 yuan from March 6 to April 5, then your bill is wrong. You overcharged 405 yuan on the last bill. The money you paid back will be deducted from the 405 Yuan You you spent in the previous period by default, but your 405 yuan in this period is equal to not being paid back.

If you spent 405 on your last bill, there is no problem with the bill.