Bad aftersales service may make problem disappear,

I bought a Hisense H50 lite cash from Heidelberg mall vodacom. At first I wanted another phone but it was not in stock. I was then offers this ****. 1 thing I needed was a duel sim phone, the agent sold me this phone and even helped transferring my simcards into new phone. Funny enough it is not a duel sim phone and 1 crd was in memory slot. I cancelled my data sim nd continued. Now this phone is shocking, it loses signal, keeps freesing, I have to reset it 4-5 times a day. I gat so many sms about missed calls. So I went to Voda and was advised the can take may phone, send it in and it will take 7-14 bus days to either fix or replace. So how should I communicate without a phone for 2 weeks, how should I do my work without a phone? And why are you willing to take money but not willing to help sort out the **** you sold me?