Yea, that's probably the best option. Vodacom should actually make it a mandatory thing [which you can unlock [EASILY] if the need arise]. I.e. if you buy a 500MB bundle you get disconnected automatically at 500MB ...same for other bundle sizes.
I've had endless issues where i get to end of month [29th-31st], check usage on see a 100MB or so left...then the 7th i get my bill and time and again i went over by 50-100MB [R100-R200 aditional costs] even when i tried my utmost best to use up 100MB AND Not go over. In the end it really came down only having 50MB [and not the 100MB the site showed at that time].
Either way, thats why i moved to prepaid options, because it just gives me so much ease of mind. I can start a 100MB download and not worry that i might be exceeding my bundle without even knowing , my connection just disconnects ....
I agree that Vodacom should, by default, enable the hard-capping option for all new contract data customers, and inform them about vodacom4me.co.za as well as ad-hoc data bundles if they need to transfer more data in any particular month.
For existing contract data customers, Vodacom should send out an sms to inform or remind customers that a hard capping option is available on vodacom4me.co.za, IOW for existing customers, give them the option of enabling it themselves.
Also, similar to the vlive APN, browsing the vodacom4me.co.za site should be possible once hard capped, so that customers can change the hard capping setting or buy an ad-hoc data bundle.
Finally, when buying an ad-hoc data bundle, there should be a checkbox that by default is 'checked' to hard-cap that ad-hoc data bundle, as well as the option of changing this later on when the bundle is nearly used up.