I'm guessing from the words "K reg" that you're from the UK. Don't call the Police, they're busy enough over here making sure the speed cameras work
They will not unlock your car for you - they'll just tell you to call the AA (if you're a member or call a locksmith).
Don't start playing around with car opening until you know what you're doing and have the proper tools to minimise the risk of damage.
It's cheaper in the long run to call a local locksmith (make sure you have proof of ID - I always ask for this on car openings).