Michael's Reward certificate NOT honored - crappy customer service harrisonburg va

My reward certificate was refused. It had not expired nor had it been used prior. The certificate stated that all I needed was to bring it to the store.  I had it on my phone and I had my Michael's reward card but I did not know what phone number I used. The manager would not honor my reward certificate.

I tried calling the corporate headquarters but after 30 minutes on hold for a supervisor, I gave up.  Why do they have a rewards program if they are not going to honor their certificates?  I will never shop there again, there are many other options for all their products.