speed increases happen from time to time but they do not usually incur a cost increase - if you bill has gone up because of that then afaik thats wrong - on the other hand they do have annual price increases - there is one in progress - if thats what been added to your bill then that would have happened had your speed not increased
you need to talk to them to clarify whats happened - try this
dial 150 or 0345 454 1111 and follow the prompts to - 'thinking of leaving us' - then "technical issues" - dont worry about that they do much more - open 8am -10pm 7 days a week - should take you to a UK call centre
they may be able to offer you a better deal - if you are out of contract and want to leave then you need to give 30 days notice - if you are in contract and the increase is due to an annual price increase then you can leave - again with 30 days notice with no penalty
ahhhh sorry - i did not pick up from your 1st post that the phone is/was not an option - i will flag the thread but not sure that will take things anywhere as staff here are very limited what they can do on accounts
Thank you for reaching out to us in our community and welcome, I am sorry to hear you package price was increased without your knowledge,
I have had a look our end and will be happy to discuss the findings and review your options. so I can help further I will send you an invite into a private chat, please click on the purple envelope to accept.