Less data package to the one agreed on.

MTN offered me 120 package deal since I was cancelling my contract, I took it and a year later the package was reduced without informing me. Now when I call to enquire about it and request the recording from when the contract was offered and agreed, I'm being sent from pillar to post, with most of their agents dropping the calls on my ear while I wait.

I have ran out of options now....