Vodacom Customer Care Refuses to Listen/Assist

I recently signed a new contract with Vodacom at their Vodacom 4u store in Cape Gate. After using the NEW phone (Galaxy S6) for a week, on the 7th day I realised that the battery is depleting at a rapid rate. I took the phone back on the next day and was told that it has to be sent away for review. The OBF (Out of Box Fault) was sent the to Vodacom Customer Care repair centre. After 2 days they rep**** to say they cannot unlock the phone due to my finger print lock. Myself and the consultant in store suggested a phone reset to bypass the phone lock. The repair centre then responded by saying they cannot and DONT want to reset the phone as it sometimes fixes the problem. At this point I started having a sense of humour failure. If resetting the phone might fix the problem then why not do it? Also it is a battery issue and I'm pretty sure it will not fix a faulty battery by resetting the phone. Now the repair centre wants to send the phone back for me to unlock it and then they said the cannot accept another OBF back as it is past the 7days return then. No one has an answer for me. This is unacceptable and I am not accepting a faulty phone back that is only a week old!