Uk Student Visa Trouble

Location: Hong Kong

I need some advice asap. I applied for a student visa and had my bio app around the 20th of August. After calling the UKVI and emailing them several times, through the past 7 weeks almost, I have received no decision letter. My last day to arrive at uni is the 13th of October, which is next Monday. I was curious if I could link my e-visa to my UKVI account without the decision letter so I tried doing so and all that showed up was that proof cannot be showed for your immigration status when trying to view my e-visa. After this, I used the UKVI chat bot to ask about my e-visa and I was connected to an agent. I told him my details and he checked my case and stated that I cannot see my e-visa because a decision had been made on the 12th of September that my visa was refused on the 12th of September. It has literally been a month since then and I have constantly called the UKVI and all they have said was that a decision was made but not what decision and I had no timeline for when to expect my visa. Do I trust this agent who told me my visa was rejected a month ago and that I’m cooked? Also is this even legal? They made a decision a month ago and are holding 3,500£ of my money and I cannot claim a refund until a decision has been sent to me. ISTFG they’re holding my money hostage and because of that don’t want me to receive my decision letter so I cannot claim a refund in my IHS. I escalated my case 4 times through the past few weeks and I have had no update, just that I will receive my visa soon. Idek for sure if my visa was surely rejected, I’m just going off what the agent said, but I have told the uni of Bristol to defer my place. I literally let go of a uni offer at HKU, as I’m from HK, just so I can go to the UK and their immigration department has ruined my future. Wtf should I do and can I take legal action against the UKVI for holding my decision for almost 4 weeks, taking more than double the processing time stated on the website, and keeping my money hostage?