You will have to do a manual recharge here. But I think you'll also have to cancel Auto Recharge as it will next try to recharge in the original date thereby giving you less than 30 days on this next manual recharge. But I would suggest you give Boost a call to confirm.
The PIN would have been the four digit number you set up that saves your credit card details.
CORY | I do not work for Boost or Telstra.
Boost Care: 125 8881 or 1800 026 678 . Or Live Chat 24x7: http://livechat.boost.com.au