Poor Service and Attitude From Vodacom

I have been a loyal customer of vodacom for 13 years and I recently did an upgrade like have done many times before. I was over debited nearly 2000 rand from my account forcing my account to go into negative and doing so penalized with additional charges by my bank. I have been dealing with vodacom customer services and they have taken a whole week to let me know it will take another 7 to 14 days for them to refund my money. Through this whole process I had to ask them to apologize for the mistake they made as none of their reps even said Sorry verbally or written. Vodacom has caused me hardship this month as I did not budget on this amount and they just don't seem to care. How can I ever trust vodacom again.