Hello, I am Keith, one of the experts on Just Answer, and pleased to be able to help you with your question.
This appears to be a common problem with HMRC's IT system which they either do not know how to fix or actually do not wish so to do.
I would suggest the following two pronged approach:
Write a letter of formal complaint to HMRC with an envelope headed COMPLAINT CASE and put this in as a header of your letter also.
At the same time complain to your MP. HMRC react much faster to MP's inquiries that they do to individual's where a delay of 6 weeks in response is common.
I do hope that I have shown you a way forward with your problem.
Thank you for your support.
This problem with HMRC online systems has been the subject of repeated complaints. The standard HMRC response is that the refund has been sent for "security checks," but no-one will be able to tell you how long it will take to get through security checks as that department cannot apparently be contacted. The online system is effectively giving false information if the payment hasn't actually been sent out but it would appear nothing has been done to resolve that issue.
If you have cash-flow issues as a result of this it is worth raising this with HMRC. Sometimes this accelerates the payment. Personally I wouldn't bother, just initiate the complaint and the MP's routes immediately.