In 2009 I learned I may have been mis-sold this policy; so I contacted a company in Manchester (advertised over Spotify) and they thought I could win, but after speaking to them I discovered they would take 50% of any compensation received. So... I did my research and found the PPI Reclaiming guide on Money Saving Expert: http://www.moneysavingexpert.com/reclaim/ppi-loan-insurance.
I meticulously gathered all correspondence (including the hand written notes I made during my application for the loan) and progressed with their 3 stage approach.
I sent the stage 1 letter to Tesco and received a few "we're very busy" type letters for a few months before eventually receiving a document explaining why they thought I was wrong and their "surprise I hadn't cancelled the policy already" and made an offer of £750 as a goodwill gesture with the assumption I'd be happy and consider the case closed and not take it further. Well this letter actually annoyed me, so I called Tesco and cancelled my PPI policy (which I hadn't realised I could do) and sent the stage 2 letter. This was almost immediately disregarded as they wanted additional evidence. As a stage 2.5 letter I sent a copy of my hand written notes made during my initial application. Tesco still weren't convinced so I called them directly asking to speak with the person responsible for my claim. I attempted to bargain, but he explained there is nothing more he could do and just suggested I go to the Financial Services Ombudsman. I declined their £750 gesture.
I forwarded all my correspondence to the Ombudsman along with Money Saving Expert's stage 3 letter. The Ombudsman also took their time but sent regular letters explaining what was happening. After 3 months I received a call from an adjudicator asking to explain my position and answer some further questions they had. At that point they agreed there were a number of points in my favour and another 3 months later (more than a year after my initial complaint) I received a letter from the Ombudsman informing me that Tesco will settle my complaint as recommended by their guidelines.
Unfortunately Tesco took their time to finalise my claim; the ombudsman stated I should hear from them within 8 weeks. After 12 I emailed the ombudsman explaining I'd not heard anything. I'm not sure if this email catalysed any reaction, nor was I sure it was read. But ultimately 2 weeks later I received a cheque from Tesco Personal Finance for a lot more than the £750 they tried to offer me.
My advice? Forget about all these "claim back your PPI" companies - as they'll make a fair amount of money out of your claim. Just do it yourself - admittedly it took 18 months, but all it cost me was 4 first class stamps and the time to print out 3 letters which I downloaded from Money Saving Expert!