Can Airline Frequent Flyer Programs Reject Rewards Points Transferred from Credit Cards?

I'd recently logged onto Asia Miles (who are affiliated with Cathay Pacific) to work out the mileage requirements of an overseas trip.

Total : Asia Miles XX,000 + HKD XXX.00 for 1 adult
Note: The listed Asia Miles required are for all passengers. Fees and taxes imposed by government, other authority, or by the operator of an airport, and carrier-imposed surcharges are not covered by your miles and must be paid separately. The fees, taxes, and surcharges shown above are for reference only. The actual required miles, fees, taxes and surcharges for all passengers will be displayed on the Miles Required page.

Based on the above mileage calculation, I transfer Credit Card points across and proceed to redeem flights as you would. The following prompt appears:

The miles in your account are not sufficient for your selected itinerary and Asia Miles Top-Up is not available. Please select another destination by clicking on "New Search" link.[Error.IBE_USR606_CHECK_MILES_NOT_ENOUGH_MILES]

I call up Asia Miles/Cathay (who's Call Center is outsourced to the Philippines) to inquire and was advised that almost double the amount of mileage is required for the required route (which was not expected). I explain that other Frequent Flyer Websites (Qantas & Singapore Airlines) do not do this, they apologized and advised that unlike other Airlines, their website has it's "limitations". From the looks of it, it's clearly a system error. Emails with screen shots had been sent to their Travel Services Center, to either honor the redemption or reject the rewards points back to the source. Their response was, we are sorry but there is nothing we can do. I no longer want to fly with Cathay. Can Airline Frequent Flyer Programs Reject Rewards Points transferred from Credit Cards?