Shockingly bad service - KIA

I have serviced my 2010 Kia Sportage at this branch since new but it seems they are currently totally understaffed and poorly managed. I booked my Sportage in for a major service a week in advance and asked them to make sure the parts (especially cambelt) were available. They accepted the car yesterday morning and told me it might take two days (which is fine by me). However, yesterday evening I received an email that the parts would only be available next week! I emailed back that I would like a courtesy car but there has been no response and I have tried phoning a number of times today and the switchboard person cannot get through to the service consultant or manager. I have left messages for them to phone me back but no response, It seems I am to be left without transport for the next few days unless a miracle occurs!