You may well have found this already but you can download an RSPCA Comments
and Complaints leaflet here. Might be of some use.
http://www.rspca.org.uk/utilities/fa...entsComplaints

The self help group might be able to offer some advice about making an
effective complaint
http://the-shg.org/selfhelp.htm

Or you could always try emailing the RSPCA CEO Mark Watts directly


HTH

Tim