They do seem to have decided kbps means bits not bytes.
The result is ludicrously low traffic management speeds on the Basics package.
Yes as on the Basic package you only get a maximum of 50 Kbps (including overheads) at peak times and so in practice not even dial-up speeds and it is supposed to be a broadband package !
If I was forced on to that package then I would leave O2 along with the phone service and migrate to another ISP !
I would probably go back to Zen as I know they didn't throttle but had download caps which I could live with as I managed with them before.
I also found their customer service first class.
I only migrated to O2 from Zen to save money
not because of poor service.