Paying for 2 contracts

Hi..I was called by your call center to an upgrade..I made it very clear that the upgrade must only start in December after the new one finishes..the agent agreed..I now get sent a bill for the new contract and old contract..tried complaints department Esai Naidoo responded once was waiting for the sales call...4 days later still nothing. Sent another email to say I am escalating..still no response or call..**** service for a complaints team...call the calll center they say they will put me through to retention.. wait for 20mins no answer...tried again wait..finally when they answer phone gets puts down....Bosa network for yourselfs not customers Reference number: 6d5b315e-8db1-4cbe-b2a1-d95b9274c375