Why is it so hard to get UK VAT Registered - Help!

I’m a USA based book author and started selling on Amazon UK in October. My one product is a book that I’m selling in the North American and UK Amazon markets. I have applied 3 times to register for UK VAT, starting in September. I got one rejection letter saying they weren’t satisfied with my proof of identity and then applied 2 more times via their new online application form, and have not had a response to either of those attempts. I called the VAT office and got this phone number 0300 322 7870 which was supposed to get me to someone who could give me more information, but when I call it I get a fast busy, and I’ve written to this email vrs.newregistrations@hmrc.gov.uk.

Does anyone know of any other things I can do to actually connect with someone in the HMRC VAT registration department in order to figure out how I can get VAT registered. I am very close to having Amazon shut down my store, and given that I’m a one product seller, I can’t afford to sign up for Amazon’s VAT service.