Vodacom using my airtime as they please

I have a prepaid number which I only top up to make calls but accidently when I have the data icon one, Vodacom feels entitled to automatically take R10 for 3MB of data without requesting me to have a say.

This has been happening for the last few months and I've done the normal routine of using the USSD code of, *135*6# to cancel this data refill and am told I will receive a sms once it have been cancelled, I've tried it twice now with no reply, phoned the call centre if they are able to cancel it immediately but the turn around time is 48 hours

First off if I wanted to purchase a data bundle with my airtime I would use *123* when I rechange but I don't need the data as I have a wifi network.

Please cancel this with immediate effect as it is another way Vodacom seems to have found a way around of using my airtime without my consent, like a wasp service.

Your quick response is hight appreciated, it's currently in escalations and tomorrow most likely I would rechange again only to lose R10 for 3mb.

I have months of sms's sent to, *135*6# to cancel the data refille but never a reply received to say it's has been cancelled and the cycle continues.

Thank you