My family is annoyingly calling constantly my home?

They're envious people and call us many times a day just to annoy and take our peace away. I'm thinking of buying something to proof their constant calling and what's said on the callings.

Thing is my cellphone doesn't register many received/missed calls (just 5 or 6) so I'd like to know if there's a cellphone out there that does so, so that I can buy it. Iphone, maybe?

Another thing is, if I buy a voice recorder, will it record just the voice? What would I do about the hour of the calling? Can a voice recorder inform the hour as well?
Will a judge accept the hour I've set in my recorder/cellphone? Or will it just accept an official hour? If only official, how can I find an official thing to inform the hour of the calling?

Would a micro-camera be any good? Should I install cameras at my home so that I can record when they come to ''visit'' us?

Sorry, I'm just 22y.o. And I've been facing them over the last 5 years, since I lost my dad. Things got worse lately. Even my mum got ill. I must do something. Thanks in advance for any tip.

Added (1). Thank you. What do you suggest me to do, then?

The legal system does not exist to settle minor petty issues like this. Do you imagine some judge patiently watching your videos and listening to your recordings? It doesn't work that way! You can't take legal action against someone unless they've broken the law and you are paying an attorney to handle your case.

You need to man up (or woman up) and deal with this maturely and directly with the parties involved.

Also if you ever did use the legal system they would get angry about the vagueness of your claims ("take our peace away" "Envious people" etc… ) The law loves facts and hates feelings.

The number calling you should show up.quit answering the phone when you see their number
or just hang up when you hear their voice if the number doesn't show up.change your number and don't give it to them. You can buy phones that come with answer machines, but their land lines
you need to plug in to use. You have several choices here. Get a phone that has caller ID, get a land line phone with an answer machine. Any answer machine records the time and date of the call and
the length of the call.don't answer the phone after and before a certain hour.put your car where they can't see it and don't answer the door when they come over. Which family members are doing this?
if all else fails, move far enough away that it's too far to drive for a visit.

BUY AN AIR HORN and answer with it.