TERRIBLE SERVICE

i recently purchased a contract for a samsung galaxy j and a tab3 the j seems to be working fine but the tab gives me endless problems from day one, the screen works when it feels like working, i noticed this fault in the first 7 days of purchase and took it into store for OBI reasons, in was advised that it will take 7 working days! after the 7 days i contacted Mrs Lalitha and she kept telling me its taking long to come back, eventually after i hounded her she tells me shes sorry she has not being at wok she will sort it out when she gets to work. 14 days passed and i contacted the store, they were very un-helpful blaming the factory for taking long. surprisingly after i phoned last Friday which was 15 days of the tab being gone, i was called back on Saturday being told the tab is ready, i picked it up yesterday and the problem still persists. this is rather frustrating, i am paying for something that doesn't work, and they refuse to replace it. i am disgusted with the customer service of this cell c branch! i feel like the tab was never even sent in or OBI as they so quaintly put it. They probably gave me the tablet back without even sending it out the store. i am very displeased