As I've already stated, anyone with less than 12 months service will not be able to claim any sort of unfair dismissal (this will change to 2 years after April).
I asked Mrs P (she's an HR consultant) about the contract and she said that you can have what is called an implied contract i.e. someone employs you, you go there to work, so you have a contract. A written one is always preferable, obviously.
Think you need to take this as one of life's kicks in the plums, as there won't be a lot you can do about it...