Can I book another flight on same date, of existing flight?

[dracut77]

Hi,
I am looking for clarification on one of the offer of Amex.
I booked one ticket with ANA with my Amex card in December end. Couple of days back, I got offer on my Amex account, "spend $1000 on ANA and get 25000 points".

Can I just book another ticket on same flight and once I get confirmation, cancel older one and I will be still eligible for points?
I am seeing conflicting information on this. Some forums says "your refund would be processed, and that would be a negative spend on airlines, so over all you'd not be spending on ANA you'd have a credit on ANA. You can't use the AMEX offer. It will be the sum of your spend in the promotion period which because the new ticket is cheaper will be a credit to your account.". While some suggests, I can cancel existing one, and then rebook and still I will be eligible to get the offer.
Can someone clarify this?
Thanks

[MrDisco99]

FlyerTalk is probably a better venue for this question.

[pizzadude]

Is the original ticket you purchased a refundable ticket ?  To me that would be the biggest concern if you can't get your money back if you decide to cancel it in the future.

[K-in-Boston]

If the original ticket is refundable to the original payment method, the purchase threshold for the Amex Offer would be offset by the refund.  (Example: original ticket was $1500, you buy a new ticket for $1500, but you are refunded $1500 - your net spend is $0 for the offer.)  If the original ticket is refundable only to an eCredit, then the new purchase would trigger the offer.  Two other things to keep in mind are that depending on the fare class purchased, even if the ticket is refundable there may be a charge for doing so, and airfare is very dynamic in pricing so there is a chance that booking now may cost more than the original ticket.  If your travel date is far in the future after the Amex Offer end date, it's probably unlikely that Amex would claw back the credit if you canceled the original ticket well after that date.