I had won a development kit with 3 beacons in a hackathon in Cyprus a few years back and as I just started trying to use them I got the message that they have been claimed by someone else. The funny thing is that I just opened the box.
Valerio,
Devkits gifted during hackathons usually come with a slip with activation codes inside the box. If yours didn’t, or if you misplaced the slip, I will be happy to manually assign the beacons to your email address.
Please send me a PM with the beacon identifiers (you can check them using the Estimote app) and your email address, and I’ll get right to it. 
.
/Timo