In reply to Greenbanks:
https://www.ami.org.uk/find-an-instructor
Take a look on here under South West England. I am not based down that way so I haven't come across many of the instructors operating in the area. I can recommend Mark Stevenson on the basis of having climbed with him on a meet and chatted in huts, very knowledgeable, friendly bloke who's clearly happy to share his knowledge.
This isn't to say anything negative about the others of course!