I brought a month subscription but when I try to create PDF, it directs me back to the monthly subscription page. Have contacted iTunes & they have refunded my £7:99 but suggested that I reported the problem before I try to subscribe again.
Thank you for reporting this.
I would suggest you to please visit the link below and try placing the order there:
On this page you can change the country at the bottom left corner and choose your suitable plan accordingly.
Please let me know if you still face any issue trying to subscribe to it.