Takes less than 5 minutes on the phone and it is all sorted. If they ask if you want to discuss your reasons just say "no thank you". They might call back during the months notice period from an 0800 number. Either don't answer it or ask them not to call again, the first time they call.
Thank you for taking the time to write into the Community, welcome
I'm very sad to hear that you're considering leaving us, I would suggest as the members above have, (Thanks guys), but would love to know if there's anything that I or one of the team can do to change your mind? If there's an issue that you would like some help with we can certainly help.