not helpful and very bad attitude

I bought a lumia 720 last year march, already three times i have taken it back to the shop because of the phone going blank. They keep it for months on end each time but when we request a new phone they say the battery was low. Am i so stupid to take a phone back to a shop for a low battery? And why would vodacom keep it for 3months each time cause of low battery? The consultant himself(mbuso) charged the phone in front of me before taking it to repair and nothing happened. What im most upset about is the disgusting attitude of the manager. He was not helpful at all,instead he was cheeky and ill mannered. I cannot be paying for a phone which im not using and not in my possession. Im very upset and if i do not get re-imbursed and given a new phone or the contract cancelled. I will be forced to take further legal actions against vodacom as a whole. If the consultant and manager cannot assist me and instead make me they puppet. Ill get my lawyers to intervene,maybe there ill get proper assistance.