Jacket has become very thin

Jacket has become very thin

My Patagonia nano-puff jacket has become very thin. I’m not sure if it has lost some stuffing or if it is worn out. My jacket is 3-4 years old. Is this a repairable issue for Patagonia? If not, can I exchange or get my money back. This was a $ 200 jacket and it doesn’t seem right for it to wear out.