Ezybonds has no control over your orders, only the processing of a payment from another Ezybonds member's Ezyaccount to your Certified Merchant Ezyaccount. Payments are processed based on: 
  1.  the details in the POSTED form data from the Payment Button on your website;
  2.  the availability of sufficient funds by the paying Ezyaccount member; and
  3.  what your Notification Script logic says to do when the Ezybonds payment server communicates with your Notification Script. 

Only you have control over the processing of orders based on your verification of payment.
If the customer has opted out of the purchase by cancelling or even just closing their browser window then you should not process the order based on both lack of payment and date/time judgement. 
The Check and Payment steps in your Notification Script verify payments in your ezyaccount and are for your use in authorizing a payment as well as updating your own data base as to the result of payments made to your Ezyaccount through the Payment Button. 

Once an order has been recorded on your database and the customer has clicked through the Payment Button and been presented with the Ezybonds login payment page to complete the transaction, they will either login and make the payment or their payment attempt will be declined. If the payment is declined it will be due to either lack of funds or your notification script. 
 
If they do login and they have sufficient funds and continue through the prompts, the order will be checked through a communication with your notification script (the Check and Payment step responses) and if all is okay the transaction will be processed. You will be notified of the payment by Ezybonds and your own database should be updated with the result of your notification script communication: Transaction ID, etc. If the payment has not gone through then your own database will be updated by this response from your notification script as well.