Unknown porting of number

I called vodacom to do a Sim swap they told me u have my number under ur company how come I don't know, I don't even think of any day porting my number from vodacom to ur company I haven't given u authority to take my number. Where do u get the permission I can't change to vodacom to something I don't know please release my number I can't abandon my number that I've used for 15 years because u guys ease