Mate, you can't be this dim surely?
At the end of your contract you OWN the phone, you can do what the hell you like with it, you can even go on PAYG if you want, or even sell it to one of the many places that buy them.
You cannot compare this to renting as only a small portion of the total monthly payment is actually a rental payment. (Line rental is usually circa 7-15 quid a month depending your tariff.) If you want most mobile companies will just charge you for line rental alone if you don't want a phone.
The rest is going towards your eventual purchase of the phone as these things are EXPENSIVE, but your mentality seems to not be allowing you to place a perceived value to it.
If you were to buy an S2 they are currently about £450-500 on the net to buy outright.
he does not get it... he's thinks its like temp employment, were if you 'win' a 2 year fixed contract it is much better than getting 1 year...