NEW PHONE SWAPPED AT REPAIR CENTRE FOR REFURB UNIT

I bought (22 Oct 2014) my mother-in-law a new blackberry phone for a Christmas gift. We found that the scroll button was faulty. She only handed it in for repairs on 15 Dec 2014. She was contacted stating Vodacom will replace the phone. She received the 'new' phone on 29 Dec 2014. Immediately she noticed the battery dying within an hour of using the phone. Upon inspection she saw the battery looked old (wear and tear marks). She went back and the battery was replaced with a new one (14 Jan 2015). When she still complained about the battery life I inspected the replacement phone and found a 'REFURB' sticker on the inside. I took the phone back to the repair centre and they flat-out denied it being a return phone but rather a 'newly assembled phone'. Apon booking the phone in for repairs the warranty start date for this phone was listed as 10 April 2013!!!! They still denied this being a used phone.... I have all the repair slips, IMEI numbers and proof of the 'REFURB' phone start date. I called Vodacom customer care on the 28th of January. They asked me to mail all the docs. I did so the same date. I have e-mailed 3 times after that and called twice. NO FEEDBACK AT ALL AFTER 10 DAYS