It is enough you address it to
PIO.
Even if it is addressed to a wrong person, he has to send it to the correcct
PIO.(I think section 7 of the act deals with such a situation).You have to send the first appeal within 30 days of receipt of information from the
PIO or within 30 days from the date on which reply was due( that is 30 days from the date of receipt of your application asking for information). Best wishes.
latelearner.