Calls are going from my number to an unknown person, but I am not making the calls.

Assalamualaikum..! I have a Jazz number which I have been using for a long time. For the past three to four weeks, I have been receiving calls from unknown numbers daily. I usually don't pick unknown numbers. If I happen to be using the phone and a call comes in, the caller says that I had called them, even though I never made any calls. I have no balance and I don't dial out. I called Jazz helpline and informed them; they said there is no such activity from my number. I have filed an online complaint with NCCIA but I don't understand what is going on. If anyone has any idea about this, please let me know...