Poor service in store and customer complaints!

I have purchased a wifi modum on the 15 November 2017 at the Telkom store on the Bluff in Durban . Its 12 day's later and the modum doesn't want to charge. I went to book in the modum this morning were I was told it takes 21 working days. I am not happy about this waiting period as im going to pay for a modum that I wont be using for 21 days. If I wanted to put another sim card into my phone I would have baught a sim card only! As this is a fault with the device. I won't be told by a consultant to take the sim card as use it like that as I said earlier I purchased a wifi not a sim card! When I asked to speak to a Manager to speed up the process I was told the manager is not there! How can a store be open without a manager to assist customers who has problems and compliants?? Or should customers be waiting for a manager to get back to the store one day to be helped?? As this is a lack of service and very unprofessional. Also on the day of purchase I didn't receive documentation with the terms and conditions or the returns policy for this device. I refuse to wait 21 day's for a device that is faulty as it was not damaged by myself. I also refuse to pay for a device that I am unable to use. I have sent a complaints yesterday to the customer complaints and still no feedback from them guess poor service is throughout Telkom.