Rating sellers that cancel

I wish Mercari had a way to rate sellers that cancel for no reason. I bought something just 2 days ago that the guy sent me a counter offer for and I accepted. He then canceled our of the blue. I messaged and asked if everything was alright and he says, "that's less than half what I paid for it." Like bruh... YOU sent me that offer! "If you have a problem, take it up with Mercari, not me" is what he then proceeded to tell me. Wtf man. I was really excited to get the item too 😭