Bad Attitude.. Breach of Contract.. Bad Service...

I have been a Vodacom customer for over 15 years.I have a rolling contract & I pay insurance (no claims).My upgrade was overdue so I visited Vodacom Centurion Mall hoping to upgrade.I wanted a white samsung but because there was no stock I had to settle for a black one.At home when I wanted to insert the SIM card,I noticed the sim slot was damaged.I took the phone back the next day.I was told the phone had to be sent for repairs despite the fact that I returned in 7 days.I feel this is extremely unfair.The staff were unwilling to listen me. I left the phone there. In the days that followed they called me to come collect the phone.The phone was not fixed and not working. I insisted on speaking to the manager and he was rude and not helpful.He actually told me to go to another store for help!I went to the Mall at Redds store.From there I was told to go to Vodaworld in Midrand.I went to Vodaworld and left the phone there.Now,i received a call from them saying I must pay in R1800.I haven't even used the phone.They debiting my account and its over a month. I'm a over 60. I don't drive. I have to pay people for transport o the stores each time. It's costing me money. I want it cancelled