Using virgin modem instead of hub

[Zairs]

I bought a modem off ebay to replace my hub, but when i set it up it doesnt work and says i need to phone up. i'd prefer not to as they will probably not be happy about me buying one off ebay even if they understand me, is there a way i can set it up myself?

 

[Zairs]

they would have activated it, but they said it was only able to go up to 20mb, so they have fiddled with the hub again. though they did say if it didnt work they would do me a modem if i want