Ineffective contract limits and useless customer service

I have a contract in my name but the user of the mobile phone is someone else. I placed a small limit on the contract of R50 to ensure the line isn't abused.

This limit is ineffective. Instead of paying the contract amount of about R400 a month, my bills are regularly above R750. When I email Vodacom (I live outside South Africa and when I call the call centre I'm told by a voice prompted system I've exceeded my free access to the call centre!) I get very generic emails saying that Vodacom isn't responsible for the ineffective call limiting system. It's also very clear from the content of the replies Vodacom's agents are pretty clueless in understanding my issues or even trying to resolve them.

Now, 3 weeks after logging my latest query, when I log into MyVodacom - my call limit on this account is still 'processing'.

I've given up with Vodacom. Honestly I can't see how a network can get worse than this.