Virtual assistant - handle bookings

I run a phone repair business in Newcastle, Australia and I need someone to handle my bookings. When a customer books through the website, you'd be sent an alert on your phone (it requires an app, so you must have an iphone). Within 5 minutes (10 maximum), you'd have to accept the booking request and then phone the customer within an hour to confirm the details of the repair, confirm that their booking is within the service area, then enter the repair into my calendar. You'd also be responsible for altering bookings and assisting the customer with basic inquiries. The volume of bookings is currently quite low, so you'd be getting a maximum of 5 booking requests per day (currently around 2-3 per day). Due to the low volume of repairs, I'd prefer to pay on a per-job basis, but if the volume is higher than expected, I'd be open to moving to an hourly rate, this is open to negotiation. Since the bookings can come in at any time, you'd need to be near your phone from 6am - 3pm AEDT time.