Poor to dismal service336

Our phone line was out from 11/12/17 to 05/02/18. So far no credit has been made. Have phoned 10210 several times, the latest this morning. Waited forever for someone to answer. Couldn't help as system was offline. On one occasion I was given a dispute resolution reference number but this has made absolutely no difference. Poor service but being a government department and a monopoly I suppose it is to be expected.