You can get some members opinion's on these types of "scheme's" from this thread. As you will see, they're not too well received - I suspect the "month's" delay is a bit optimistic K.
It's the same principle as a pyramid scam mate. basically only the people in at the top get the chance of a new phone. You pay your £20 and go in at the bottom. You are then relying on others to bump you up the list. Problem is that when you are 6 levels down in the list you need huge numbers of people to join so that evryone on level 4 (for example) can move up a layer. Eg. Layer 1 is 1 person. He gets 8 people to pay £20 to get him anew phone. Layer 2 is 8 people. They need 64 people to get them all a phone. Layer 3 is 64 people who need 64 x 8 people to get them a phone (and so on). So unless you're at the top you're knacked. CL