my daughter had endless problems trying to get talk talk to solve a similar problem and eventually an openreach guy came out and founf there was water leaking through a box outisde the property, talk talk had failed to provide continual service i..e broardband and landline due to this fault not being dealt with at the address, instead they kept dealing with the exchange. They refused to give her any credit for the monthly bills that she paid over the period of the fault, i intervened, googled who were talk talk's ombudsman contact and rang the customer relations dept at talk talk, asked to speak to the boss of each person they kept putting me through to until i could get no hight up the chain and then said i had a prepared letter to send to the relevent ombudsman, (can't remember which covers talk talk) and the guy on the phone wiped 2 months bills for her,