I work at a retail store and I deal with customers with returns and exchanges everyday. Every retail store has some kind of return policy that they have to follow so LP wasn't picking on a specific customer or situation. At our store, we have a return policy of 90 days for most items if you're not satisfied. But after 90 days, you have to contact the manufacturer yourself for any warranty issues. That is based on date on your receipt/invoice not on how many days you actually get to try it. LP had to follow their policy, over 30 days, and so they had you contacted Aeris. This return policy is pretty standard in most retail stores.
It's unfortunate that a new item would fail so quickly. In our electronics department, I have seen the same item, brand new, came back the next day because of malfunction parts while other customers didn't have any complaints. That is QC of the product and in this case happened to be Aeris. You just happened to receive a bad product unfortunately. It's an inconvenience and we do feel for your frustration.
To be fair from a third person's point of view, I think LP didn't do anything wrong and sometimes customers misunderstood and expected the dealers to take full responsibility. But that again was because they didn't understand the rules. There is a line between what dealers and manufacturers can and can't do.
As to how LP interacted with OP, rude or not, that would be a different story depending on who you talked to and how experienced he/she was. That could make a difference in an already disappointed customer.
Good luck to you and hope things turn out fine.