On en it is absolutely forbidden for an admin to unblock themselves
(unless they have the consent of the blocking admin, for example when
testing things). An admin blocking another admin is frowned upon and
would need a very good reason, but it tolerated under some (rare)
circumstances (eg. you have reason to think the account has been
compromised, although you would actually need an emergency desysopping
in that case).
So, in your situation, I would say you were definitely in the wrong,
the blocking admin was probably in the wrong.
You should have requested another admin to unblock you, just like any
other use would.
The blocking admin should have gone through the proper channels
(ArbCom or equiv.).