For some reason I didn't get the one ui 4.0 for my phone and I have been waiting too see if I would be able to get it？
You might have to wait a while or contact your network provider since I think the update can be received faster by some due to their network providers. Also, you might want to go to software update in your settings and see if you can manually download the update.
Beta will not be available for all users even if you have eligible devices. Not necessarily network issue if you have an unlocked phone that can beta test and the limited slots are filled within hours of opening up.