Suspicious Rude Employees

Last week Thursday my hubby bought a sneaker at cross trainer. On Sunday when he opened the box to wear it, he noticed they put the incorrect sneaker in the box. Obviously we had to wait for the next weekend to take it back which was Saturday. We took the sneaker back with the slip and they refused to change it as they say it had been worn already. The sneaker has definitely not been worn by my hubby, and we would not try to return sumting that is used. The lady and man was rude and swearing and shouting when we tried to tell them. I have supported cross trainer even tho their prices are ridiculous for over 10 years. And generally spend about 50k minimum per year at this shop. They have definitely lost my business and I will never recommend them to anyone. The only thing I can think of is that someone from their shop has used the sneaker and put it back in the box. It was not even the one my hubby choose in the first place. ,that is why we tried to return it. But we was treated like ******* at Cross Trainer Trade Route today. Will not support them again.