Dischem Brooklyn went back on their word

I had a problem that I emailed the Dispensary manager, Liana Pretorius, about and she agreed via email to assist me to sort it out. At the time, she was not in the store and then when she was, I was not able to go in. Today, when I went in, suddenly she can't help me anymore due to the time frame being too long since the email. How does one tell a client you will assist them and then change your mind. She was not available before now, plus she never indicated any time constraint in the email to me. What shocking client service, but then the store is not the same, since the old dispensary manager left. He was tops! I won't be buying from Dischem Brooklyn anymore!