The mos unprofessional, rudest store manager!

Could you believe that Secret Location's store manager asked my friend to stop shopping at the store because she returned a pair of shoes? To make the long story short, my friend has been their customer for almost a year and has spent literally thousands of dollars there (the store is not cheap). She had bought a dress which turned out to lose its colour and smearing everything it would come into contact with. So, she returned and the store agreed to give her "store credit". So far , so good.
Last week, my friend bought a pair of shoes (over $1,000) but she wasn't sure if she really liked it after she took it home. But she thought if she could use the store credit, she would keep it. The shoes were not used at all and we were still within the store's own policy of 7-day full refund for returns. The manager quite unreasonably said my friend could not use the store credit for that purchase. So my friend decided to return the shoes and buy them back. The manager told the sales associate that it was not possible to do that! (I should say the coward manager didn't dare to come out and talk to us in person; he talked with the staff on the phone all the time.)
So my friend got upset and returned the shoes for good. Guess what? Not even a couple of minutes after we had left the store; the rude unprofessional manager called my friend to tell her that she could not shop at the store anymore!
At least based on my experience, this is unheard of in Canada, if not anywhere in the world with decent shopping culture! So, I hope the owner of the store gets rid of this so-called manager; as he is a disgrace not only to the store but to the businesses in my beautiful neighbourhood, Gastown!