Change landline number

I rang on Friday and spoke with customer services re changing my land line number. It has fallen into the hands of scammers. I was told this would be completed by 8pm on Sunday and to ring 174 or 175 and I would be told my new number. This time passed and nothing happened other than I was told it was the wrong number.  I have already wasted over 6 hours of my time in phone calls trying to get Netflix reinstalled. I have no intention doing the same with my phone line. Please advise.