Vodacom upgrade

‭A person saying he is from Vodacom called me on Friday from this nr(+27 (31) ***‬) . and presented me a very attractive cell phone upgrade package.

So much so that I could cancel my current add-on data package.

When I spoke to Vodacom cancellations earlier this morning, they knew NOTHING about the package that was presented to me(Smart M Plus), 2,6GB data, 200 min talk time iso my current 120min.

I currently pay R331.35 incl a1Gb data on Smartm package.

How can Vodacom allow operators like this while they know nothing about them?????