Mercari shopping haven’t been received although it says it is

Hello all, I have a question about mercari japan. I bought a book and paid through conbini. Mercari says it has arrived but actually it has not. Yamato on the website says the same. I checked with the seller and he says he does not know my address and that only mercari does. Anyway I contacted meecury saying it has not arrived and that I checked with Yamato already. I woke up and found the transaction canceled. I am not sure whether it is the seller or mercari especially that I was not happy and sent the seller that I am disappointed. I did not get the money back so I am not sure what to do in this case. Could someone give me some pointers?

by nutandshell1