Some questions on dial a phone.

ALTeration

OK so I have found a number of deals, I just have a few querys as to the way some of the cashback works (yes I know it's a potentially dodgy transaction, but I am very stingy and have specifically chosen contracts I can afford without cashback, plus I feel I can trust dial a phone more than the other sites), for example there is an automatic cashback, does this come at the end of the contract or at particular times throughout the contract. Or there is the claim based cashback, which I would like to understand better, is there any hidden charge for making a claim? I was worried when I saw this line at the bottom of some of the terms "Itemised billing is not included. (Can be requested at a charge of £0.99 per month)This is a minimum 24 month contract." just in case they have other charges like this.

OK so my second question is what is the difference between the simple 500mb allowance and the 500mb UK Blackberry internet and email. (maybe this is the wrong place for my second question but someone might know)

I would be very grateful for a response and will gladly accept opinions etc...