EXTREMELY BAD SERVICE!!!!!

i took out a Telkom contract via MONDO last year October and received the device late in later the same month. Upon using the phone for the 1st time i realized that there was no sound on the telephone at all and called them to replace the device. the device was collected about a week after and since then i am still awaiting a replacement. I've been calling their customer care on end, except for being on the line for almost 20min at a time I've been made promises of follow ups, feedback from a manager, reimbursing the months that i have paid and every time i contact them i was promised to receive my device the following week. Yesterday i received an SMS with a RMA number saying i should visit my nearest Telkom Branch for them to replace the phone. i called Mondo just to confirm that this is correct and i was told by the agent that's exactly what i need to do. after taking 2 hours out of my busy schedule i visited a Telkom branch only to be told that there are no record on their system whatsoever. This morning i called Mondo yet again and actually got hold of the lady the named Thule who sent me the SMS ans insisted on speaking to a manager and the same story was spinned to me that the manager is either unavailable or in a meeting. again i was promised that the manager will call me as soon as his available.............finally i received a call from a manager? i don't think so, i had me to call them again at 4:30pm only to hear that my query will be escalated to management. HOW DO YOU MANAGE A BUSINESS IF YOU CANNOT TENT TO A CUSTOMER"S NEEDS???????