Unhappy Cell C customer service

My husband has been a customer at Cell C for close to 20 years.His one contract upgrades every 2 years end Jan beginning Feb for a new device.Got an sms informing of renewal of upgrade. Got to Cell C store 28th Jan to be informed upgrade took place sim only no device for R369.00.Very unhelpful consultant says nothing they can do must phone call centre on Monday as they are closed at the moment.Tried call centre on the 28th after leaving store got ***** line as did not agree to deal transfered to call centre spoke to agent Rulani who was helpful advised will change deal to device will pay R349.Will be delivered by Monday as there was stock.No device delivered .Phoned call centre 30th,31st no joy transfered to different departments holding on 20 to 25 minutes at a time trying to resolve. Finally called again today and was told security questions were answered incorrectly. Seriously how is one supposed to resolve this matter .