Worriedperson

I am slowly being driven to the brink by HMRC and their delays in refunding me my SEIS refund on my annual tax return. I am due a 15k refund from an SEIS investment (which I need to now pay bills) and the delay of which is having some really terrible knock on consequences for me. I have tried to call HMRC multiple times and each time it says we are currently having technical difficulties and simply hangs up. It has been 6 weeks since submitting my return, what am I suppose to do now if I can't contact anyone and it is having a really detrimental affect on my life?