Vehicle Asset Finance account

Hi <br> <br> I purchased my vehicle back in 2011 and fixed the rate at 13%. However, over the years the instalment always increased when the inflation rate went up. This should not have been the case as per my contract the interest rate was fixed. Now, I've already requested a copy of my contract, which I have since received. I would appreciate urgent feedback on this matter please or I will have to report this. If I picked this up then so many other people are being missled as well.<br> <br> Many thanks