An update.....
I contacted my local Jaguar dealer and they said it would cost £192 for the diagnostic process and then they would quote me for the work. I asked if I would be able to get discount being a premium member of this forum and I was told that due to my car being over 3 years old I would automatically be entitled to a discount that was better than what I would get for being a premium member, when I questioned them further it turns out that the discount was the same as I get here.
Then I found a local company that specializes in everything DPF, they were brilliant on the phone and said they would come to me, diagnose the problem, clean out the DPF and check for other problems that may have caused it for just £200. I have read all their reviews on various sites and they don't appear to have had anything bad said about them.
Just need to make an appointment with them now.
Many thanks