Keeps freezing and highlighting not working

Im seriously frustrated with the Kindle app right now as it keeps freezing and doesnt let me highlight any text. I also keep coming across many pages that are just blank and Im not really sure if I missing content or if theres just that many blank pages but it doesnt seem to make any sense. Im reading text books that Ive downloaded to Kindle from Amazon and this is making it extremely difficult to complete my homework assignments. To top it off I tried to press the app support button from here in the Apple Store and all it did was take me to Amazons website and that provided an FAQ page but didnt give me any real option to contact the support team.

Lunahayes about Kindle – Read Books, eBooks, Magazines, Newspapers & Textbooks, v5.13