You should do a Quiet Line Test, to ensure that your PHONE line itself is in good condition.
As you can do the QLT at no cost and in your own time, it is well worth dong before deciding on any change of ISP etc.
And it will also benefit FTTC/VDSL etc as well.
Also you should do a QLT about every year or shorter, particularly during and after spells of bad weather' and that you have a long line which is likely to be more susceptible to related problems.
Edited by deleted (Wed 08-Jan-14 12:21:01)