HOWEVER!! The Kindle version which I received was full of typos, missing letters and missing words. There were enough mistakes that it passed through annoying and actually affected my ability to follow the story. To their credit the publisher contacted me directly to apologise and asked for examples of mistakes. I've provided some examples but have not heard back, nor do I know how to verify that current versions of the Kindle book have been fixed.
I don't recall any formatting issues in the version I read.
In the past I bought a (self published, I think) Kindle book that was poorly formatted and Amazon refunded it immediately.
£25/month? There are plenty of cheaper plans with lots of voice/data for around £10.
For example GiffGaff:
£10 per month: 500 UK minutes, Unlimited UK texts, 1 GB Internet
£12 per month: 250 UK minutes, Unlimited texts, Unlimited Internet