Poor response

Vodacom deducted my wife's account on 30 Oct instead of 31 Oct. There was not enough money in the account as I only paid in the money for her deductions on 31 Oct. As we are in Singapore, my daughter asked them to deduct the money again. They then stated my wife had to write a letter requesting that, which she dutifully did and sent it per email. We then received an automatic response with a number. then my daughter started getting threatening sms's. When she went to the service dept in Stellenbosch, she was told that they could not see the letter on the system. We sent the email again. Got another automatic response with a number. Every time we were told it will take them up to 5 working days to respond. They then cut off the phones of both my wife and daughter on Friday 20 Nov. And we received an email with a threat to hand over my wife's account to the legal dept to blacklist her, etc. Is this really what Vodacom's service is about? If they were so absolutely pathetic in their service, why did they not just tell my daughter right in the beginning their service is so ****** pathetic that the best way to avoid frustration is to go and physically pay the money?