I have bought an item but how do I find out the sellers address to collect it?

Hello I bid on an electric bike which was described as being in "very good condition". However after I had won the auction the owner told me that  the battery was not good . So after corresponding we have agreed that the sale should not go through The seller was polite and accepted that his description was not accurate. I am not complaining but he did ask me to write to TM and explain that the bike sale should not go through. the sale reference is:  P231309145: regards, Rosaleen  Edited in line with Community guidelines