Unrecognised outgoing calls

[zsak]

My history shows calls to numbers that I don't recognise.  I only make voice calls to one number, my house.  Not even by accident do I ever call another number.  And I don't answer calls from anyone except my house.  My wife and I text only.  Only four people in the world know my number.  We have phones for emergencies only.  I use my phone for about four minutes per month.  Therefore, it's easy to spot outgoing numbers that are not made to someone that I don't know.

Question: How is it possible that someone uses someone else's account to make calls?  How do I stop this?  Whom do I contact to look into this?

Thanks

[zsak]

One of them is to a '4001' number but the another is not. As I said, only four people in the world know my cell number. Also, I've never checked my voicemail because there's never anything there. If there is, it's a robocall and I'm not ineterested. I have a separate number for 2FA texts and no one but the institution(s) knows that number.

Thanks for the reply BTW!

Cheers

[softech]

@zsak 

are those calls going to number ends with 4001 ? or 4002?

if so, you are safe.  The usage log will record those calls coming to the VM as well as when you check voicemail.  So, this is normal.