Sooo..... what do you do if you're being stalked?
The advice given by Gavin DeBecker in his excellent book The Gift of Fear is to ignore them until they go away. It may be tempting to try and reason with them but it is likely that they will see any dialogue as an encouragement.
You should let your family and friends know what is going on so that they don't pass on any information accidentally. If it is possible to change your phone number consider doing so.