I have unlimited minutes. There is one particular number which most but not all of the time, after about 8 minutes, I will get a recorded message saying that if I continue the call, I will be charged. The call then disconnects. I am not charged.
Sometimes, it will disconnect without the message at the 8 minute mark.
And sometimes it will not connect and the call is a normal one.
The number is a standard residential UK landline. It is only this number that has the problem.
Any ideas?