Help I've been scammed?

Hello, I'm new to this internet scammer thing so I'm pretty scared.

I was selling a phone and the buyer suggested he send money via bank. I agreed. He asked me to send him £30 through bank first to prove I'm "legit" me being me did so. It came through in about a hour and 1/2, this person then Reckons they sent the money to my bank, nothing shows up(I waited a night) person says their bank said it can take 3 days even thought it's through mobile banking? Still nothing. So this person asks me to send £60 through to him/her to prove I'm legit and he/she will get their friend to send it. Me being stupid and not thinking anything of it complies! They then turn around and say "I've changed my mind, I think you're scamming, even though I have supplied pics ect!) and say they want their money back(which I haven't got?!) and say because it's "processing" (fyi they wouldn't show me proof they sent it!) they want £220 of me! The firstly threatened me saying they'd go to the police(still got no money here!) then the second time they'd come to my house!
It's my first time selling on the Internet so was pretty clueless. I'm 16 years old so I'm pretty scared! I was only selling a phone, but I've decided after that experience I'll take it to cash converter!
Please anyone got any advice? I've lost £100 and they're threatning to come to my house(even though they don't know where I live, they said they tracked me down?) I'm pretty scared right now!

Unfortunately, you have just learned an expensive lesson. There is absolutely no earthly reason you would ever have to transfer money to a buyer.

They are low-life scammers, plain and simple.

Just drop all contact with them. If they keep bothering you, filter their emails to trash, and ignore any future contact with them. It would help if you posted the emails they sent you here (remove your name) because they are undoubtedly running the same scams on others.

As to the threats? They figured you weren't going to fall for the "send money to prove yourself" a third time, so they just decided to see if they could scare you into sending more money. It's typical bluster of a pathetic criminal. But, there is no reason you can't file a police report to document both the scam and the threats, and on the (unlikely) chance they are somewhere in the country (these scammers often work from overseas) then maybe someday there is a chance of them getting arrested.

Even if someone had transferred money (and these scumbags didn't) you have every legal right to wait until the money is actually in your account to return it (and it would be stupid not to do so.) There is no law that requires you, a private party, to send money out of your own account to refund a payment you have not received.