Unmasking no caller id calls- iPhone

I have a friend at my work place that is being harassed with countless phone calls. We're aware its by someone from work as he has been called in by said person for a "meeting" at work that obviously didn't exist.

I've heard of websites that allow you to unmask the numbers so instead of it saying "no caller id" the number will come up and we can report this to the manager/ police. However, they're all subscriptions and would prefer something thats free.

Would the phone provider be able to give my friend the number thats ringing him or is there another way to find out who this person is?

I guess another option might be to block anonymous calls on the iPhone but would prefer to know the number.

App fluctuating space usage on iPhone?

I have the Tumblr app on my iPhone and sometimes it says it is only taking up about 260 MB of my phone's memory but sometimes (like right now) it takes up 1.2 G of memory. Why does this number go up and down? I just recently updated it. Could that be why?

Will spotify take money from my bank now?

I was planning to get Spotify premium because I suppose I need it really (can't live without music)
and I have no money in my bank but have just got out of overdraft as well (I'm with Barclays and I was subject to fraud so I never made payments to get overdraft) but I was wondering as it is a free 30 day trial and if you don't cancel your subscription you have to start paying… As I have no money at the moment, will it take ANY money out of my account until the 30 days is done? Also am I correct if I save a playlist or album to offline mode, my iPhone will not use data and I won't be charged by O2?

Can an Iphone4 be used without a data plan?

I have an extra Iphone in a drawer and wanted to use it solely for text and talk. Will prepaid unlimited talk & text without data minutes work? I will never use the data functions of the phone. No Fb, twitter, GPS, etc. Just talk & text.

My cousin is a spoiled brat?

My cousin is 21 years old she lost her parents 8 years ago she lives with her uncle he spoils her a lot. He lets her do whatever she wants and doesn't care. And she thinks she's better than everyone els. He even let her marry a guy who's old enough to be her dad. Her husband is 44. They live at her uncles house. She's even got an iPod touch and an iPhone and a tablet and a computer. Her uncle said she didn't need an iPhone because she had the iPod that calls and texts and does all of it but her husband got it for her anyway. She doesn't go outside much she just stays inside in her room taking pictures of herself with her phone. She even has a charging speaker for her iPod. And she gets to go to every concert she wants. She's even going to see Kiss this summer but she got mad at her uncle because he couldn't afford a meet and greet for her. Now she's mad about that but she's still excited to see them. Her husband has two kids from a previous marriage and they're her age. I think that's crazy. And she loves music and every time a singer she loves gets married she gets mad and says she's not listening to them anymore. I guess that's normal for a young girl but it's kind of weird for her since she's already married. She and her husband have been married 5 years. She was 15 when she got married he was 37. They were dating for only a year. But she was crazy about him. Her uncle let her get married. Do you think she's a spoiled brat?

What is going on with my twitter?

Every time I go to tweet/dm/favourite/rt/follow on the iPhone twitter app, it says there's an error. It has been like this for 48 hours now and I really need someone to tell me what is wrong as it's nowhere to be seen online!