How can I arrange complete new phone line.

Hi, 

I have had trouble with my land line crackling from November last year. I  do get clear periods when it can be used but they are few and far between. I have reported it 6 times, had an engineer once and told line was fixed. The wiring outside my property is very old so think this might be the problem but nothing is done. The only solution I believe is to get a total new line but don't know where to start. The advisors ( from India) try their best to help but in my case I am still with no phone.

Any advise appreciated. Maureen