Immediate Payment to Bidvest never reflects.

Every single time an immediate payment has been done into my account, it does not reflect. I call Bidvest hours later, I am then asked to send POP. The last time it took 4 days to reflect. Today, i sent the POP from Nedbank that clearly states 30min, again 5 hours later, i called Bidvest and again they request POP which i have mailed them. These are funds that i require IMMEDIATELY - hence the immediate payment. But Bidvest does not come to the party. 2 hours after the mail - and still no response.