Error while entering activation key

Hello,

I bought 6 days ago a dev key to upgrade my MyBookTable version,
but an error say : “Clé de licence invalide : Impossible de se connecter au serveur. ” witch mean something like : “invalide liscence key : unable to connect to the serveur” , i’ve contacted author media support, but they took like 3 days to answere asking me to give my key (it’s what i’ve done) but no news since 3 days,

so here’s my question : did someone had the same probleme, how could i solve it ?