It is not possible under any circumstances to incur additional charges for having exceeded the maximum Flybox consumption.
When you have used up your available amount, your connection will be simply slowed down.
It couldn't be simpler to recover your usual surfing speed: just buy a new surfing top-up (Konnecta Booster).
Via Orange Yame
You can top up directly your Flybox Konnecta using Orange Yame menu.
You can download the app here.
From Orange Money
Ability to top-up the internet account of your Flybox as and when required, for the pleasure of the entire family by dialing *145#.
Via an Orange shop
By visiting your nearest Orange shop.