I immediately roll my eyes at anyone who claims to have been “shaking” over having to return an item to a shop, and would assume that “the adviser was rude” is probably code for she wouldn’t give in to what the OP wanted.
I absolutely know that there are rude people in customer service, I have worked in a webchat team and I have also worked in call centres. But the customers who have accused me of being rude have typically done so because they were the ones in the wrong and I’d had to point this out to them.
Like the customer who came through to demand the £200 offer we had on on a bank switch the week before, except there had been no offer, not for months. But she was absolutely adamant, demanded to make a complaint, demanded the £200 plus compensation for her distress and because I was apparently lying to her, and in the feedback she then said she looked forward to hearing that I would be fired as a result of me lying to a customer.
Or the ones who come through to complain that they weren’t eligible for the bank switch incentive because they haven’t brought across any direct debits, and are adamant that they did, Netflix and amazon, and won’t be told that those aren’t direct debits they’re regular card payments.
Or the one who, when I worked for an insurance company demanded a refund on his insurance which he had to cancel because he’d lost his licence for drink driving, and wanted his entire annual premium refunded because he had to cancel it and hadn’t made any claims.
Every single one of those would tell MN I was rude, and I absolutely wasn’t.
Oh and “the customer is always right”? Complete and absolute bollocks.
There’s no need for rude customer service. That being said, retail and customer service staff have been expected to put up with rude customers for decades, and it’s become out of control now.