Im sure you all hate banks as much as I do so I thought I should give you a succes story from Joe Public.
My Missus god bless her has never been great with banks etc and before I met her she had a couple of loans for cars etc and had been misled into taking out the Payment Protection Insurance that in days gone by you were led to believe was not optional and increased your chance of being succesful.
I had a look through her old paperwork using a simple template letter and a first class stamp sent a complaint letter to one of the big banks............result 16 days later, a big fat cheque for
£2000 now this is not free money as she had paid it out when she was on her uppers but we did get a nice dollop of interest which is the banks own cash
It appears she was lucky to get paid straight out but there is a great chance you would get some or all of your hard earned back if you have had this insurance even years ago!!
Im onto the second one for a similar sum and given the current climate I'm loving every minute

The moneysavingexpert site has a good guide on it but I would advise staying away from the many agents who do it for comission, it is pretty easy to do yourself.