Sorry I totally understand.
Actually I contacted Hifiman about the exchange (to the updated version), they asked me to send back the existing one first. But after some talks with the nice customer service lady (Miss Guo), she agreed to let me hold the current one until the updated version is available
My understanding is.. we hold on to the can and return only when we received the new one.
Think dr Fang did mentioned this in this thread... Let me see I can find it... Hopefully I am not dreaming..