Available balance does not add up

I'd like to raise a complaint with regards to My available balance. Earlier today I sent an eWallet transaction of R100 then I had an available balance of R4136. Following that I spent R1013.99 at Shoprite Eyethu Mall and I expected my available balance to be R3122,01. To my shock, as there was no other transaction after that, my available balance is R2783. I tried to chat to Jarred on Secure Chat to explain why I have a shortage of about R340 but he was of NO help! He keeps saying I need to go get a bank statement to see all my transactions. I don't need to a statement to see that my available balance does not add up and I can't see where that missing amount went.