Mobile Out of Order: All apps/software not working

May '15, received notification to upgrade wapp on Nokia Asha 502.Unable to complete as error msg saying file missing. At same time, Twitter stopped working, although different error msg. Also could no longer store pics or open pics. Went into store per Cell C call centre. Mobile sent off for 21 days to Pretoria. Came back with same issues unresolved. Booked in again, this time for Nokia customer support. 21 days later, received phone, again - nothing fixed, & told memory card *******. As card is working in other phones & in card reader, I can't accept this conclusion. Was told that the issue is with Nokia technology, & Cell C is not responsible for 3rd party apps. I must sort out with Nokia. However, phone is still in contract period, was sold to me by Cell C, with their endor*****t, and I am a Cell C customer, albeit a very unhappy one. Cannot understand why I need to deal with Nokia, on top of dealing with Cell C . Was told to send email detailing all the above by manager of Cell C store, for forwarding to head office. It is now 3 weeks later, & I have not even had the courtesy of any response. So from mid-May to Sept, I have not had a working phone. Great customer service, hey?