Yes, you can sue them. First you need to log (or go through your phonebill) & highlight all incoming calls from them. You need to establish enough evidence to file a police report for telephone harassment. I did find out though, if you don't pick up the call, the history of that call does NOT APPEAR ON YOUR CELL PHONE BILL!! If it's a cell number, set the ring tone so you know who is calling each time from that number.  If you want to ignore it, set it on silent.  If you want to FIGHT them & bring justice, ANSWER the call each time & keep somewhere (probably in a word document or in your daytimer) an area where you log every single call they make to you - date & time! Highlight all phone bills.  

Here is the law on cell phone harassment  (put this in your address bar hit enter) http://www.privacyrights.org/fs/fs2a-cellcalls.htm
Here is the law on telephone harassment:  http://www.safetyed.org/help/stalking/castatute7.html

AFTER you have collected the evidence - you can telephone (look it up the regular number) the OC Register & ask to speak with the person highest up who has the authority to do something. It's likely these are just telemarketers paid very little money taking out their frustrations with that telephone punishing - at will - anyone they target who said NO the wrong way who approached them with a solicitation call. YOU are probably one of them. (SO am I) After you have the evidence - call them, tell them you're about to file for a restraining/protective order - or simply inform them about what is going on.  The people calling you don't have a direct line going back to when you call the number there may be 100 telemarketers & that ONE number shows up on your caller ID, still it allows you to create evidence of the harassment (better for you).  Pick your poison, inform them politely & hope they stop or go after them & bring justice for you & everyone else............ If you live in OC, (you must if you're getting the calls) you may even get the name of the person who would be VERY concerned of this problem (they are probably not aware of it) & tell them what's going on & if they do not do something you will push legal action to the fullest extent.  

hope this helps!