Hi,
A restriction may have been placed due to a billing issue. The line can receive calls, and can make calls to emergency services or talktalk customer services.
This can only be resolved by the account holder calling TalkTalk diectly, 0345 172 0088 or via live chat : https://www.talktalk.co.uk/contactus/making-a-payment#679
Our billing teams are still available.
Karl.