Hi,
We operate a hotspot portal where users can register for a new account and get 30 mins free access per day. Account can be recharged to get additional minutes. We also generate cards for premium user for logins without registration and payment at this hotspot.
We often see that users take the username/password from the cards and register with these data and their personal information. Unfortunately the residual credit of the card will be overwritten with the free product that is given for all new registered users. So users complain that they did not get the minutes shown on the card.
Why is it possible to "overwrite" an existing user (from the card) by a new registration? Normally there comes a warning that the username already exists.