***** case- no feedback, no refund!

I submitted an affidavit to Vodacom for a ********** upgrade on my account, which I discovered when I was billed double what I should have been billed. I had to call the call centre a couple of weeks later to get feedback and I was first told that the matter was closed and there was a credit on my account. I didn't expect to be charged double again in that month but I was. I'm tired of calling that call centre and this works quicker. I need my money back asap. My ref number I was given at the time was EC-OW-2IQCLH. Help please...