upgrade to a faulty product

Upgraded to a Sony M4 Aqua mobile was faulty I returned it the 3rd day they claim even though it's out of box failure they have to send it awayand I must wait 5 to 7 days it's the 8 th day and no feedback from the store, this is my 2nd post on hello Peter and the only response I got was that an email has been sent to Vodacom Vangate mall store manager Clinton the consultant I returned the mobile to is Darren, Vodacom has also Breached there contract stating feedback to be given within 5 to 7 days. Im definetly changing provider and would really like to put closure on this pathetic disgusting inconvenience caused by Vodacom.