Letter template to cancel TalkTalk account
Crib notes from it, or cut-and-paste the whole thing. Of course, they might try it on and aim to fine you for leaving your account early, but if you're willing to stick at it, they should let you go.
Send your letter to: Customer Relations Department, TalkTalk Group, PO Box 346, Southampton, SO30 2PW
You'll be giving them 14 days to reply and sort this out, which is the law. If they don't, you can cancel your direct debit with them as they're in breach of contract and indicate that they're acceptance of your terms within the letter.
Give 'em hell!
Letter Template To Cancel TalkTalk Account After Data Breach
Dear Sir or Madam,
Account number: [account number here]
It is clear that you, TalkTalk, are in material breach of these clauses and, with the hack in October 2015 being the third on TalkTalk's systems within a year, this represents a clear failure to secure my details. You have failed to take the agreed safeguards and have failed to secure my, the customer, personal details, which has resulted in my personal information being exposed to third parties who do not have consent from myself.
As a result, I want you to terminate my contract without any penalty. I will insist that you send written confirmation to me that will allow me to move to a new provider, without cost, within 14 days of receiving this letter.
After the 14 day period, you will receive no more payments from me, and should you proceed to harm my credit over non-payments, I will be forced to take further legal action over any costs accrued.
[print name here]
[write account number again]