Have you tried connecting at the test socket? See here for more details:
https://community.talktalk.co.uk/t5/Articles/Your-guide-to-main-phone-sockets/ta-p/2205432
Subject to that, if you would like the support team to look into this for you make sure that your personal details including TalkTalk phone number and/or account number are complete on your community profile (click here) so that they can link your forum identity with your account and then wait for them to respond tomorrow.
