I can't blame them becaue if someone wants to buy something and have the money for it, it's not their duty to figure out if the purchase is right for that person.
You can blame them.... You went to them trusting they would be professional and get you set up correctly. Just because you had money to spend doesn't mean they had totake it by selling the wrong arrows to you. They could have still sold you the right ones for your setup. I'd tell them what you found out and tell them they lost a good customer in the future.