trailing arm bush

Has anyone else had a vivaro / trafic / primastar for test where the nearside trailing arm bush has seperated from the steel outer ? . Had 4 in the last month . Always nearside , always chassis bush , always had arm move to outer edge of mounting . BUT the rubber insert is tight in steel outer & cannot be moved with pinchbar . I have shown these to presenters & advised the bloody things because there is no movement to be felt , so you cannot fail for worn as it not excessively worn or likely to become detatched .

Local vauxhall agent deny's having had any in for replacement when I rang & asked !