This is a tricky one because the fault is clearly with Royal mail rather than the vendor. Yes you can dispute because ultimately you’re entitled to get what you order and you can even do a late dispute once you’re outside of the normal time period. That does however seem very hard on the vendor who has done nothing wrong. Depending on the value of the order you may want to consider putting this one down to experience and bad luck.

How did it go to the wrong adress and how did you actually find out ?

Oh my god that is my worst nightmare so sorry that happened even more sorry that someone got a nice little freebie off you they should have returned to sender or at least used common sense and delivered to rightful adress after all its the kings possession until it arrives at its rightful recipient hope you get sorted mate