Hello my bear
I admit i also have many issue with the english language, but after reading this, it gave me some sort of relief in considering that isn't so bad after all...
So, let's start.
My main problem here, is understanding exactly what are you trying to tell us.
After 3 looks at it, i have the impression that the current problem you are facing, is 2 users (presumably using vouchers), being able to get access to the www by using the same voucher at the same time, so, multiple users for just 1 voucher.
Is this the problem you are having now?