Self assessment refund referral

I have been waiting on a refund from my self assessment for almost two months. It has been referred and still nothing. When I cal the helpline I am told they are just payments and the processing team are uncontactable so there is nobody I can speak to find out what is going on. How do I escalate and what is the specific procedure when something has a referral?

Hi,
Repayments are randomly selected for further security checks, can take much longer.  
We cannot comment in this forum on your particluar situation, for that you would need to progress chase via our self assessment helpline on 0300 200 3310 or contact our webchat facility at:
Contact HMRC
Please have a look at the guidance at:
HMRC compliance checks: help and support
Thank you.