Unsafe dog food

I bought a bag of dogfood full of mite, called the number provided on their website and spoke to a guy called Josef. He told me to mail and I did, absolutely no response since. Is this the type of customer support we get from them? Makes me wonder how safe the food is for our dogs? He told me the food got wet, in a sealed bag? It was mite and not mold, its telling me the problem is from a dirty factory? I am not happy with how it was handled, definitely not a friendly person this Josef bloke.