Cheating customers out of ther money

On Friday 12/09/2015 I did a sim swop on my no and the balance of the airtime was R660.00. I then decide to upgrade to the Apple ihone 4 which they advertising R129 with 300megabytes of data free for 3 months.<br> <br> On the Saturday 13/092015 the upgade was done. To my surprise all my airtime was gone. On the 14/09/2015 when I receive my airtime, no additional data. I was told if you change from one plan to another you loose your airtime, however in June a contract for my husband was also upgraded to minutes the airtime still shows if you do a balance enquiry therefor he did not loose his airtime.