Issues with a stalker. Can I get some advice?

Not looking for advice of what to do about a stalker, but advice on what you might think. My ex left me in early January. An old thing she used to do before leaving me is call *67 so I wouldn't know it was her. She wouldn't say a word, but I just knew it was her. She likes to play games. Since she left me in January and up till 3 weeks ago I would get a random call labeled 'private'. And as soon as it started to ring, the call would drop. I sent a text message asking if it was her calling with no reply. Then in mid April I got notice that my ex was getting married to another man she has been engaged to since last year June. Yeah, I know what you are thinking, the math doesn't add up. She just left you in January, but has been engaged since the prior June? Yeah, messed up. I took it hard. Then May 30th came and up till that point maybe 3 to 4 'private' calls with hang ups before I could answer. My 30th would had been our 3 year anniversary. The next day, I'm driving home and she pulled up next to me at the light on her way into work. Later that week on Thursday I pass her at a store, but she didn't see me, at least I thought so. That night, I got a 'private call' that dropped before I could answer it. The next day I am at the DMV getting stickers for my car and she's there with her future husband getting him his license issued. She saw me, we stared briefly at each other. I thought about things for a while, then sent her an email telling her that I am hurt from what she has done but forgive her and miss her. The next day it started... Private call after private call. up till last Friday I counted in around 110 calls, but the difference was there was no hang ups. This person just sat there listening to me answer. I'd ask who is this and stuff but no answer. I'd hang up then they'd call back. It stopped for about a week, then I sent another email to my ex and it started up again. I have only given my number out to one girl since my ex left me and it was at about the time all these calls started. I asked her if she was doing this to me and she said no. Now the calls have started again but this person is saying something. not comprehensible words but like grunt noise. I'd ask if they were going to finally say something and there would be a uh-uh like as in a no. and some uh-huh as in yes. The person calling is a girl, I can tell from the tone and have also heard other things in the calls, background noise. When my ex would get a text message come in while talking on the phone with me, there would be this certain tone, and when her phone was getting low on battery I would hear another tone. Tonight, I heard the battery tone that sounded a lot like hers, and a couple days ago she called and I heard a text come through her phone. I've asked repeatedly if it was her, my ex, but got nothing in response. I don't know though and also have to think this could be the other girl I gave my number too a couple weeks ago. I know this is kind of long but if you have read this and have some insight, please let me know and thank you for the help.