Appointments+ default to please select for service

Hi, when the list of services is shown it defaults to the first entry thus we find some users then go to the calendar and click a time without setting the correct service. Could this be default to a blank value and they need to select. Also is it possible so that when they check the service the available times is refreshed without clicking the button. Again we found that its easy to change the service and assume the calendar reflects the correct times. thanks Paul

PS: is it possible for us to change the text of 'Service' to 'Treatment'