UTR re-opening delay for over six months

I received an HMRC self assessment refund notice to an old address which arrived at the precise time I was moving home and remained unopened for two months. The letter was asking for proof of identify and bank statements to prove my address etc. I replied to the letter and sent off all the documentation in May 23. I received a response in June 23 confirming receipt and explaining my UTR would be re-opened within 60 working days. In September 23 I chased HMRC when the UTR was still not reopened and was told due high volume of requests this could take until Dec 23. I explained that I was financially struggling because my self employment income is derived from working within TV and film and the industry was on its knees due to actor and writer strikes. I was told my case would be escalated. Dec 23 has rolled around and I submitted a complaint to HMRC via a web form. Today I received notice that my complaint has been received (3 weeks later) and that they need 12 weeks from today to investigate the matter and update me. Is there anything else I can do? The refund was for almost £4k + interest so I’m keen to get it into my account as soon as possible.

Hi

I apologise for the delay in receiving your repayment but as your Self Assessment was locked it will need to be reopened before the refund can be processed.
As you have submited a complaint to escalate there is nothing else you can do. You will need to allow the timescale provided to resolve the issue.

Thank you

Dont hold your breath been waiting since Feb 23