Strange calls from contacts

[infinitee]

Hi I own a Droid 2 Global, a little older than two years old. This morning, I received two calls, both from people I know that I have saved to my contacts. The first call was answered by a woman, the second with a young child. A few minutes later I called the second number back and my friend who has the number answered and said that she did not call me.
Could there be some kind of mistake because it really shook me up. Please help
Thanks

 

[themib]

if you are on verizon go to https://nbillpay.verizonwireless.com/vzw/accountholder/unbilledusage/UnbilledVoice.action
see which numbers are there

if same numbers as on phone, it's verizon
if there is a difference, maybe your phone, I would flash sbf and wipe data

is phone rooted, do you know which system version is on phone
menu/settings/about phone/system version 4.5.629 or other

 

[SFGate]

I have received this type of call in the past, and just recently, when I have called my voicemail, a recording has stated that I have reached the voicemail of....with 2 or 3 different numbers. When I call back one or two times, eventually, I reach my own voicemail. While the carrier will disavow all problems, it still is a very spooky situation.