Money missing from my account

Today I was at the garage and my app was acting up I then called my brother to help with cash he transferred to my Capitec account and I was able to use that cash I have 2 accounts linked to my main account ,45 minutes -1 hour later I then realised my app is working again immediately I moved R1000 from one of the accounts to the main account I went to checkers by the till I was informed my card declined but I just transferred a R1000 how possible I quickly dashed out to the atm and withdraw I was told I have insufficient funds when I check the balance it was R413 then i withdrew obviously because I needed some stuff shortly after that I called their call centre the lady confirmed the transfer between the accounts how ever there’s no indication or trace as to what happened to the R1000 SO IM HERE FRUSTRATED AS HELL I NEED TO KNOW WHAt HAPPENED BECAUSE THERES NO TRANSACTION WHATSOEVER