I didn't get a letter either, I rang them and was upgraded to the 2mb service for the same £24.99 within half an hour. Don't forget the 1mb £17.99 service is capped at 3gb per month whereas the £24.99 service is 1gb per day (30gb per month).
OnePlus 5T review: Hands-on
Illustrator Andrés Lozano on his improv line work, brazen use of colours & hand sketching
iPhone X review
Comment envoyer gratuitement des gros fichiers ?