Damaged Battery not lasting a Day

I got a message from FNB about the contract phones from Cell c i answered with a Yes and 2 days later Khosi called me from Cell c. I accepted there offer of 2 phone for R120 a Balckberry Curve with Samsung Trend Neo. I received the blackberry 1stly then the Samsung i got it on the 24th February 2015, when i charged it the battery gets finish with in 5-6 hours. I called their call centre on the 27th February 2015 spoke to Angela she promised that the phone will be collected within 7 working days. I called again on the 17th March spoke to Sello who promised me that he will arrange an emergency collection the following day, nothing happened. I called again on the 19th March 2015 spoke to Sharon she also promised and i told her that i want to cancell the contract cause am having a phone which is not working, until today i still have this phone no 1 had even tried calling me and ask did they collect or anything. I went to the main branch of FNB in Westgate mall spoke to a consulteent who helped me to call them and still nothing. I am worried that if i cancell the debit orders i will be black listed which is just not fair.<br>