I am not sure what you mean by a call ringing for a day +.
Do you have multiple calls to one extension? Phantom/Ghost calls? If so, it’s not a single call, and I don’t know how “deleting the call” would help. You need to lock down 5060, or at least not Allow Anonymous Inbound SIP Calls.
If that’s not the case, and you are looking how to hang up a channel from cli.