Lost chat history

I bought an account for around $40 from someone that got banned on MPGH. I didn't think to save the credentials anywhere else than IM since I'm used to just opening MPGH IM and copy paste the credentials whenever I forgot them. Because this user is banned or because he unfriended me (I don't know which one), I can't find the login details back. Is there a way for admins to see messages sent between x user and me so I can retrieve my purchased goods? The seller's name is "Scrooge McDuck".

I would greatly appreciate any help, and I would understand if this is not possible due to some privacy issues or whatever. Thanks anyway!