This is`nt just a talktalk scam, i`m currently getting half a dozen phone calls a week telling me my router is faulty and needs to be replaced, which it clearly doesn`t. My guess would be, that the scam is that you have to pay for the new router to be delivered, they take payment over the phone and that`s the last you hear, so if anyone gets these calls, hang up!

The phone number they use changes every week and dosen`t come up on any searches, but the code does link to India (what a surprise).