SFW lost my birth cert

...for the second time along with the ID form. I've made a complaint online through SLC, the call handler has said he'll flag it up and pass it on to Team Managers etc, what else can I do? It's been signed for on the 12th August and no-one has any idea where my paperwork is. I just need to get my ID accepted and it's absolutely ridiculous. This is for my Master's funding too, I've had to jump through hoops for them ever since I started uni and I genuinely feel as though they're doing this on purpose. Letters go missing, nothing in my online letters. Repeatedly asked to prove my British nationality despite having proved it at least three times. Picked on for 'auditing purposes' and asked to prove I have kids again and again and again.

Why do I even need to confirm my identity for Masters if I've already had three years of undergrad funding off them??? No one else I know has had to do anything like this, my old college lecturer has applied and said she ticked the boxes and all was approved in days.