Customer service of no use

We did an upgrade 3 weeks ago on a handset that they cannot get stock off even though the handset is advertised by them. Ive beem battling for 2 days now to get through to the upgrades department. Everytime the call gets cut. I requestes they call me at work which they never did. This morning i called again and got through to that department. The gentleman asked if he could phone me back as his system was slow. Guess what still waiting and its been 20min. I called again and spoke to another gentleman and halfway through the call the call gets cut again. The service is pathetic to say the least