According to your practice, 6,000 yuan of this month's bill is of course paid off, but your method of withdrawing 3,000 yuan is very particular. For example, if you manually withdraw 3000 yuan from an atm, you have to pay not only the handling fee but also the interest of 15000 yuan every day. If you can find a way not to lose 3000 yuan, you can go on indefinitely. Of course, if the cash is found out by the bank, it will be bad to use the card in the future.