Expired skincare products being sold (over eight months expired)

I recently purchased a face mask from Superbalist, after applying the face mask mask my skin became itching and felt like it was burning, I immediately read the directions on the box to make sure I app**** it correctly and then realized the product expired 8 months ago!!! After washing the mask off, I broke out in hives, the next day my skin got tight and in the evening my skin started peeling. I sent superbalist pictures of the product with the expiry date and my skin reaction and they couldn't care less, I even had to buy anti-histamines and further skincare products to soothe my skin thanks to their negligence. They did not give me a reason as to why this happened or how they let an 8 month expired product be sent out, they only sent me a 35% discount code, they want me to give them more of my money just to get a discount after their negligence? This is not on.