How could they forget to send the ribbons? They should send them to you additionally then? I don't know where to buy them but you should be able to find at least something Like It which should work too.
believe me I was shocked by their response that I didn't send them nor did they offer to sell me a new set , and when I asked to buy them I was told to buy from my local market. I have doubts they even fixed the antminer s1