I bought 2 - this navy heather and a yellow one - different manufacturers. The yellow was true to size but the blue XXL was more like a plain L.
I'm so sorry your shirt didn't fit correctly. We try to be as transparent as possible with our sizing by providing individualized size guides for each of our item listings. We would be happy to exchange or return your shirt. Feel free to email us! https://becausetees.com/pages/contact