CELL SERVICE ID DISGUSTING NOT HAPPY TO ASSIST WITH UPGRADE

I have been a cell c customer for 30 years never once a days problem now I can not upgrade and get told by 1 person yes I can upgrade the next person says I can't upgrade. I have upgraded every 2 years for the past 30 years with the same number but now I can't even the manager vusi motswela has not had the desency in phoning me back..... What a disgusting way to treat your customers staying with you for 30 years even in these trying times cell c has never phoned me for money or debit order not gone through