Even when I block this number they still are able to call me

do not answer this number they are is telemarketers they said they were something to do I think with sumo the lady was Indian so I really couldn't understand her I asked how she got my number I didn't get a straight answer so I told her they should not have my number and not to contact me again we will see if that happens but I doubt it they will just change numbers

I keep getting calls form this number does anyone know who they are and what they want if I leave it go through to message back they don't leave a message very annoying