Has my number been hacked or stolen?

I had a call from a number I didn't recognise this morning, when I answered, the caller was convinced I had called them. He had answered the call just like I did, we both thought the other had called. Got another call from an unrecognised number this afternoon but didn't answer, no message was left.
I recently moved my number to Lebara, has my number been hacked or stolen?

MillicentBystander Hmmm sounds like a perfect scam to me. If in doubt/not expecting hang up.