I'm not sure how it works in RI, but in here's what you would do in CA. Hopefully the two are similar.
#1 Start documenting all his 'attempted' communications with you. Any messages that he's leaving on your voice mail or answermachine, save permanently to tape. Document on paper anytime he comes by to see you.
#2 You've already told him not to have contact with you which is necessary.
#3 Here's where this relates to CA. Go to a court house and they'll give you restraining order paperwork. It should be self-explanitory to fill out. You list all the times and dates of the unwanted contact. You turn it in back to the court and they'll stamp it as received. Now he'll have to be served for the order to be in effect. You cannot serve him yourself. You'll need an impartial or process server to do it. Once it's served, a copy goes to your local PD, to the court and you keep a copy for yourself.
If after the restraining order is served, he'll be in violation. Make SURE you call the PD EVERY time he tries contacting you or violates the court order. Each time should be a seperate count. If he contacts you in person against the order, call the police and he should be arrested with no questions asked. If he's calling you against the order, more than likely a warrant will be sought for his arrest.
The more times he violates the order, the more jail time he'll do.
#4 Since the restraining order you just got is called temporary restraining order (TRO), you'll both have to go to court before a judge and explain your side. Then it will be up the judge to approve the restraining order and for how long. It's derrogatory to have a restraining order against you, so count on him being there to defend himself. That's if he has any brains whatsoever.
This is pretty much how it works in CA. Again, I would imagine in RI the process would be similar. Hope that helps, if you need further advice, feel free to PM me if you like or post a reply.
Also I understand you're upset and rightfully so, but be careful of what you say. He can turn around and say you were threatening him and ask charges to be pressed. I've seen this numerous times where if someone is in trouble (him), they'll try to find something to pin on the other person (you) to try and make themselves look better. Kind of like this: "well if she wants charges press against me, I want them against her"