I was on the same pay-montly contract with Three for years; then, last year, I was forced to change my contract and downgrade. With threats of quadrupling the price automatically if I didn't choose a downgrade.
The tiny print and lack of transparency led to me losing my GO Roam/ Using Data Abroad privileges. I did not want to change or 'downgrade' to the contract I am on now.
I wish I could have my old contract with GO Roam back. Cannot wait to change to Vodafone with it all included (oh wait, they are merging(!)), guess it'll be EE.