Need a Deny option when a request comes in from a caregiver

When the scheduler receives a open shift request from a caregiver, currently there is only Accept or Ignore option available. If the shift is already filled, we need an option to DENY the shift so the caregiver knows that shift is not available. Instead, if we just ignore, they keep calling us to ask about the shift. This is wasting a lot of our scheduler's time answering all the requested caregiver phone calls. If an ACCEPT option is given, there should be an equivalent DENY option so the scheduler can DENY the request when the shift is not available. I hope you can provide us with DENY option ASAP so we don't have to waste a lot of time on the phone for unnecessary stuff.