Right, thought I would update this. The problem returned so I thought I would try my luck and buy a new lock mechanism off eBay (bad move). Booked the car in with joe from Leominster vag tech to replace it and then found the door locked but wouldn't unlock lol. Luckily he knew a few tricks to unlock it and it eventually unlocked. I then knew I had to buy a new genuine one so £165 later for the new part joe fitted it and all is working again. Lesson learnt there haha.