Sold me expired stock

Absolutely dishonest company to deal with! I own a business and I opened an account with Glue Devil in Durban. They sold me 32 cans of spray paint which was expired. Within the course of a year or so, customers started returning the products saying its not working properly and something is wrong with it. Suddenly one customer noticed the expiry date and when I checked all the stock, every single can of spray paint was expired. I tried to reason with them and tried to get them to at least exchange the stock for unexpired paints instead of returning everything. They ignored me completely. They are not helping in any way and trust me they knew what they did. Always check the expiry dates when you purchase from them! Very very dishonest company.