Awful customer service

I went to exchange items I just received from SAS in South Burlington, VT. The individual who I assume was the store Manager wasn't assisting me, another associate who was very helpful, was. I was exchanging items I just got from an online order from SAS. When the associate helping me told the manager it was an exchange, the manager rolled her eyes and said we can't even sell them they are so old.

Then I explained I just bought them during SAS and no one said anything. I spend a lot at that store and based on that experience I will no longer be shopping there.

Awful experience and the first time I have ever returned anything after spending ALOT of money. Does anyone have any advice?