Disgusting and pathetic service from Netstar

I am a Netstar client for just over 20 years but the service I have been receiving recently has been absolutely disgusting.I have 3 vehicles with them.On 08 June I called retentions requesting an upgrade for one of them.Since then no fitment centre has contacted me to arrange installation of the unit.I called on 13 June and 15 June and on both occasions I was promised a callback to clarify matters.These were blatant lies by the agents(Busi,Lungile etc.) from customer care and retentions.Spoke this morning to Jamie from retentions who,in a convincing way,**** to me that her manager will revert to me and that she will also call me back and e mail me.Secondly,I did an upgrade on one of my other vehicles in April.They messed up the billing here.In May and June they double charged me for the same vehicle.Efforts to get them to call me back with a rectified schedule or even mail me has been falling on deaf ears.Their complacency,lack of respect and courtesy to customers is alarming and extremely disappointing.All I expected was a mail reflecting that they have rectified their mistake and send me an updated schedule.Also,there are refunds due to me and I need to know whether it has been actioned.So many of them lie to you so convincingly.I now regret still being with Netstar.My account number with them is 418541