Well it depends if you are on your time or their meter. If they ring you during a duty period such as a standby, then you are paid to take as many calls as they want to make I suppose. On the other hand if they are ringing you in your own free time ( off duty) to notify you of something, then it really depends if you take the call or not.
These days with caller ID you can normally see who is calling before you answer. Even where that is not the case, you can always get somebody else to answer, let the answerphone pick up or just ignore the call ( turn the ringer down if it is likely to wake up the kids). If you don't acknowledge the call they haven't served it , and will either have to find someone else, or wait until they can next assure contacting you in a duty period.
Where you draw the line is up to you. I doubt they are doing it just to annoy you even though it sometimes seems like it. If you don't want to be disturbed by them then take the same precautions you would if you didn't want to be disturbed by anyone else. Of course there are times when you are contractually available to be disturbed by them and that is par for the course.
Really, you don't have the luxury of e-mail ???
