iRule to block URI with parameters irrespective of URI query letter case

when HTTP_REQUEST {
  set uri [string tolower [HTTP::uri]]
  if { ( $uri contains "/bla/bla.asp") and ([URI::query $uri type]] equals "bla") } { 
    HTTP::respond 403 
  }   
}

Try this - change the whole URI to lower case and then retrieve the type - your failed because you were changing the response to lower case, not the URI. Yours would also work if you did:

if { ([string tolower [HTTP::uri]] contains "/bla/bla.asp") 
and ( [URI::query [string tolower [HTTP::uri]] type] equals "bla") }

That will use less memory ie it is not creating a variable but looks a bit more confusing so you take your pick.