The credit cards demand is basically an identification thing. They are using your ability to qualify for a card as a rough and ready way of confirming your identity and credit-worthiness.
There may also be a question of currencies. At the moment $10 US will buy you about $11 Canadian. And $10 Canadian will buy you $9 US. (very approximate and changing by the minute).
Are the coupon and the PP balance both in either /or US dollars? If they differ there could be problems.