appalling service regarding upgrade

Unbelievably bad experience with customer service despite being a loyal customer for 15 years. Processed an upgrade to an i phone 15 pro max in October. Was told that there was a three week waiting list for the handset to be delivered. Now in the first week of December it takes 5 calls to finally get told that there is no stock until this Friday this week but maybe i wont get the phone. then after being transferred three times call gets cut off. the customer care consultants spend more time telling me what the service staff cant do rather than how they can help me. I expect my handset to be delivered early next week or i will change my contract to another service provider where i might finally get signal during load shedding.