was ok a few weeks ago, but now the dialing tone sounds strange and when I ring out or receive a call the person at the other end canot hear me but I hear them and they sound robotic and crackly
I presume you've you've removed and replaced the phone plug into the wall socket to make sure it's clean.
Could be a bad connection in the street cabinet in which case an engineer callout will be needed.
Also check you haven't got a crossed line ... dial 174 and an automated voice will tell you if you are still on the number you expect to be.
A few other people have the same problem,BS37 area.
Thanks for your post and welcome to our community
Have you tested another phone handset?
Let me know if this is something you still need help with.