Cell C
My supercharge vanished

On the 25 october 2013 my mother bought me R 40 cell c supercharge, the following morning when i check my air time i find that all most of the super charge airtime is gone.only R12 left and i decided to check the data usage on my phone since i dont make calls, i had only used 32 megabytes for the past day. My mother called cellc and was told that i downloaded R32 worth of airtime but my usage history only showed 32 megabytes . i now want to know how 40 megabytes and R40 airtime could disappear if only 32megabytes where used??? And possibly get a refund.