Flo-Flex (was Deflex a very long time) have always had hit and miss quality. I've had bushes that have lasted years, I've had bushes like yours that weren't even fit for purpose.
If there is slop between the bolt/tube interface, there is little you can do to take up the gap beyond machining a new tube. You could try speaking to Flo-Flex and see if they'll send out a new tube in case its just a badly machined one, but equally it might be worth just returning the lot and getting Powerflex or a brand like that. Cost a bit more but you don't get this hassle