Giving out IMEI number and phone number

Hello everyone. I'm selling one of my iphones. An interested buyer asked for the phone's imei number. I didn't give it to him right away. Instead I called apple and asked a customer service rep if it was ok to give it out. The lady I asked, put me on hold and then, said yes. Anyway, I gave the potential buyer the imei. Then he asked for my phone number so he could give me a call. I thought this was a harmless and sincere request so I provided my phone number.

A few hours go by and he hasn't called/texted or messaged me. So I got suspicious and did some research and found out that my number can be ported with those two pieces of information (imei # and phone #). A few hours after I gave him the information he asked for, I called my wireless provider and told them to apply port protection to my account which they did.

My question is, do I have anything else to be worried about. Could he have done anything else other than porting my number with my imei and number? Should I do anything else to protect myself?

Thanks.