Menard's Credit Card HSBC Unfair application of payments Toledo, Ohio

HSBC processes the Big Card credit card for Menard's Home Improvement Centers.  Their accounting for payments on their credit cards is abysmal at best and I believe fraudulent.  Menard's runs Same As Cash promotions for purchases made over $299.  Sometimes it's a 6 month credit for the purchase, sometimes it's a 12 month credit plan.  As long as you make the min monthly payment and pay off the balance by the promotion due date, you aren't charged interest.  So far, so good.  

However, if you also make smaller purchases ( as I did ) while you have a promotion being paid off ( as I did ) trouble starts.  In order to avoid interest charges, you must pay the monthly min PLUS the total amount of the smaller charges (which I did on several months ).  

And here's how HSBC rips off consumers.  They will take any payment over the min. monthly payment and apply it to pending credit promotions.  Even though the total payment isn't due yet.  And even though the smaller non promotion purchases will accrue interest at 24.99% !!!

So basically, they are defrauding consumers into thinking they have the full promotion time period to pay off the promotion credit purchase.  And they are mis-appropriating payments and applying them in such a way as to charge interest they aren't entitled to.  

Haven't had a chance to research this yet, but there has to be credit card legislation against this.