DATA DISSAPEARED

We had a contract that almost almost expired as we were not sure that we wanted it upgraded. We then decided we will do it and give Cell C another change. We upgraded and on my sons phone he had R146. airtime and 2,7gb data. Son got a message saying Your Upgrade has been successfully processed. Thank you for choosing Cell c. While upgrading the phone lady suggested we take package receiving 5gb Data. Which he only received 4.7gb. She DID NOT SAY HE WILL LOOSE THE DATA THAT HE PURCHASED WITH HIS HARD EARNED MONEY . He lost his R146 airtime as well . Which she also said you can still top up on this package. I phone in this morning to report this matter held on long as they were looking for telephone conversation and then came back to me wanting to get my phone number I called in to upgrade was still talking then politely been cut off. did not take trouble to call us back regarding this matter.