Karen wants to WATCH me YELL at my Employee - r/TalesfromRetail

Karen wants to WATCH me YELL at my Employee - r/TalesfromRetail

r/TalesfromRetail - I work at (GAME STORE). The other day, a woman called and asked if we had a specific game available. I was dealing with a customer at the register already, so I told her I could check for her soon, and put her on hold.
Out of nowhere, there's a rush of people and I forget that she's on hold. About ten minutes after she had first called, and the rush is over, she calls again.
"I was on hold for twenty minutes! You forgot about me!" she yelled.
I was slightly embarrassed. "Oh, I'm very sorry, ma'am. It got quite busy and I forgot I had you on hold. Let me check on that game for you."
"No! I don't care about that anymore! What you did was very rude!"
I'm kind of at a loss since I've already apologized to her, and am not sure what to say.
"I... I'm sorry ma'am. It was an accident. Is there anything else I can do for you?"
"What, you want me to ask a question so you can put me on hold and then never come back again? I don't think so!" click
It was a rather strange interaction (not the strangest, though). I thought it was over, until about thirty minutes later when she came into the store.
"Are you Knever?" (I always give my name when answering the phone at work, as I'm sure we all do)
"Yes, how can I help you?"
"I was the one you forgot about on the phone."