Did you copy this address from your blacklist? there should be a dot between itsretunes and com.
To block audio and video you can try to create custom templates for squid and add the following:
#Edit File in squid.conf above line in ACL Zone.
# ACL for Radio / Video Stream
acl StreamingRequest1 req_mime_type -i ^video/x-ms-asf$
acl StreamingRequest2 req_mime_type -i ^application/vnd.ms.wms-hdr.asfv1$
acl StreamingRequest3 req_mime_type -i ^application/x-mms-framed$
acl StreamingRequest4 req_mime_type -i ^audio/x-pn-realaudio$
acl StreamingReply1 rep_mime_type -i ^video/x-ms-asf$
acl StreamingReply2 rep_mime_type -i ^application/vnd.ms.wms-hdr.asfv1$
acl StreamingReply3 rep_mime_type -i ^application/x-mms-framed$
acl StreamingReply4 rep_mime_type -i ^audio/x-pn-realaudio$
#End of ACL for Radio / Video Stream
#Edit File in squid.conf above line in http_access Zone.
#Rules to block Radio / Video Stream
http_access deny StreamingRequest1 all
http_access deny StreamingRequest2 all
http_access deny StreamingRequest3 all
http_access deny StreamingRequest4 all
http_reply_access deny StreamingReply1 all
http_reply_access deny StreamingReply2 all
http_reply_access deny StreamingReply3 all
http_reply_access deny StreamingReply4 all
# End of Rules to block Radio / Video Stream
I’ve found it here:
Step By Step Configuration Squid To block Streaming media Online | Linux Step By Step