Teemill complaint: Sizing discrepancy

We are trying to use Teemill as a platform for designing our own tees as we were really impressed by their ethos for sustainable and organic products. Over the months, we have had several problems and replacements given, however, our latest products, two t-shirts arrived last week, with the right size logo and printing but with sizing issues compared to the photos they show us of our product. Teemill have said the image matches the sizing given but agree that the picture shown on our website and theirs does look different to the actual sample we have been given, as the image is not an accurate representation of how the t-shirt will look. This is confusing as who buys a t-shirt to later find out the logo takes up more of the t-shirt space than the picture they are looking at??? When asked how they will rectify this, they said this is what buying samples is for, and will not be offering a refund. We are a small businesses who is trying to make our mark but cannot sell products that look different on the website to the actual product given to customers.