Unlimited package not Unlimited (False Advertising?)

Being a long loyal client of Cell C for over 10 years, it is with disappointment and disgust that I write this comment. Last year 2016 I approached cell c for a contract I was interested in the package in question was the Pinnacle Unlimited according to the adverti*****t in included unlimited minutes and SMS and 10 gigs of data. This package suited my needs perfectly. All was well up until I received an invoice charging me for my calls for over R2000 over and above the contract charge. I contacted Cell C whom informed they would investigate and come back to me in 24hrs 6 days later, with no response I contacted them back only to be informed that my Unlimited Package was limited to 5000 min per month . My question to cell c management what is the meaning of unlimited as it seems my definition is very different to what they understand it to be. And are they willing to do about this as it is false advertising in my opinion.