Upgrade gone wrong

In July 2015 i upgraded my contact with Vodacom and selected a new phone. The new phone was delivered in 2 days and all was great. a few days after the phone arrived, i started playing around with it . i noticed that the battery was faulty, it is not normal to charge a new phone every day, even two times a day. i decided i would then return the device withing the 14 days allowed for upgrades. i called vodacom on the 13th day since i had received the phone, requesting them to please come and collect the device, they sent REM to collect but i was not at the address at that particular time (they came earlier than we had agreed) for the past few 4 weeks i have been calling Vodacom almost everyday to follow up on the collection and replacement of the device . after calling the call center numerous times a team leader in the upgrades department started assisting me with this after i asked to escalate the matter . he promised to get back me to me last week with feedback that hasn't happened! i am now not satisfied with the service or the device. can somebody from vodacom please get back to me, i need this device collected in exchange for a new device or to to cancel this contract