Opting out of MTD for Income Tax

I opted in for the testing phase of MTD for Income Tax, and I have tried using QuickBooks to complete my return for the first quarter of the tax year and this has not worked - the only connection to HMRC which I have been able to establish is MTD for VAT, which is not helpful. I have spent hours on the phone with HMRC and on the website trying to find the "dedicated MTD customer support team" but they don't seem to exist. Does anyone have contact info of any kind, or even just advice to help me navigate this? I would ultimately like to opt out though - that would be ideal.

Hi
I am sorry that you have not been directed to the customer support team when you contacted HMRC. Advisers on the Self Assessment helpline have the option to transfer calls through to them.
You would also have been provided with the telephone number on the letter you received after you signed up. You opt out within your Digital Tax account by following these steps
•    under 'Next updates due' section select 'View deadlines and manage how you report'
•    at the top of the Next Updates page select the ‘opt out of quarterly updates and report annually instead.’ link
•    select the year(s) they wish to opt out for
•    check the years selected and select confirm
Alternatively, if you call the self assessment helpline, they can transfer you to a MTD support adviser. 
Thank you.