Hey Fipsy, mine did that in april this year and I replaced the mechanism myself. Was an easy straight forward replacement, I got the part number from Seat Direct Parts and ordered one else where due to the cost, literally took 10-15mins tops from taking the plastics off, unscrewing and disconnecting the plug on the original, swapping it out for the new one and testing then putting the boot back together. If I recall correctly it was a 20 or a 25 Torx bit for the two holding the mechanism in place!
I would honestly give it a whirl yourself save having to pay labour costs to fit it unless you don't want to like, albeit if you want to I can give you the link to the one I purchased unless you've already sorted it by now?
--Lee