My thoughts on how NTL should handle this are such:
Set up users on contracts like you would a mobile telephone.
I am on orange, i get 200 minutes a month inclusive in my line rental. When I use more minutes i get charged every minute i use my phone. If i dont use all 200 miutes in a month (say i use 50) it gets rolled over to the next month so i now have 250 minutes the next month.
I am on NTL, i get 75GB a month inclusive in my rental. When I use more GB i get charged every GB i use my connection. If i dont use all 75GB in a month (say i use 50) it gets rolled over to the next month so i now have 90GB the next month.
--
Other than that if they dont allow us to 'roll over' GB and charge us say £1 a GB over we go, can we get refunded for every 1GB under we are?
Hope that makes sense