Banks and building societies have been making unfair charges for many many years and if you follow our guides, you should get your charges refunded back to you.
However, if you do not follow the procedure or decide to give in at the point that your bank makes their derisory early offer (an offer of a couple of bank charges refunded seems fairly standard) and accept their offer, you may not get any more back from them.
Just remember, you are in the right and the law is on your side. Just have patience and follow our guides and you should get every penny back.