Utter disregard for customer service unacceptable

Handed iPhone 6 Plus in for repairs at Vodaworld on 19 December (still within 1 year warranty period). I received a text message from Vodaworld advising me that my phone was ready for collection on 28 December. Went to Vodaworld (30km trip) in my lunch break at 1 pm today (29th). I'm then told that my phone had not been fixed due to IMEI number not being validated and that I should not have been called in to collect at all and that this happens quite frequently. Basically my time wasted. I escalated this to the supervisor who offered to replace the phone on the spot and to wait 10 min. Note that I have now spent nearly 2 hrs there. 30 min later I inquire re progress only to be told that the phone wont be replaced and needs to be re-booked for repairs. Again wasting my time. I have been a Vodacom customer for many years and spend a considerable monthly amount. The lack of service and complete lack of respect for customer's time is staggering and obviously unacceptable. My phone is in warranty. It was cared for. I have been through the Vodacom service yo-yo. I demand a replacement unit immediately.