*********** manager and staff

I have a problem with my cell phone that I bought from Vodacom . I have been coming back and forth with this store regarding issues I've been having . Each time I requested the manager but the staff never allowed us to speak to the manager . A staff member even mentioned that is not fair that this is being done . Untill now the issue is not resolved and I am still phonelss . They refuse to give me a new phone and refuse to assist me any further as they mention I need to call a number that will be able to assist me ,which i have done several times before .they did mention that the issue is beyond them but with BlackBerry which i cannot understand as vodacom is the store that clients deal with