Exchanging a out or warranty faulty iPhone at the apple store.

Following threads on here about exchanging iPhones I thought I read that they offer iPhone 4's?

I took my 3GS and was told they could not repair the on off switch as they were no longer made nor did they have the parts but told I could exchange it for a brand new one for £119.99.

Asking which phone I would get was told It would be a brand new 3GS.

Very disappointed, did I read on here they were exchanging them for I phone 4's?

No longer made, but they had some old stock for £119.99 priceless