Fone Hijack through *21*

Someone called me that madam your courier boy is out for delivery. I said what courier He said some paper based. he said I am sharing a number of courier boy , you call that boy and speak to him. I said he can call once he reach my location. He said nahi aap call kar lo mai number forward kar rafa hun(no you call, I am forwarding his number). he send some number *21*88******** something. I sensed something wrong and msgd back I cannot call , he can call. He again called irritated arre madam *21* something..he stressed on *21* number. I said no and cut his call. I googled it's a call forwarding scam to hijack your phone. Dp not call *21* and if you have done..Google how to cancel call forwarding. I immediately