The filing payment just changed from payment pending to payment completed what does it mean

When your file your tax return successfully and you choose to pay your fees from your Federal refund, the TurboTax program considers the fee paid, even though the federal refund has not been released yet. This is why you see "Payment Completed".

It's day 24 now I've not receive my refund payment it says (A REFUND DATE WILL BE PROVIDED WHEN REFUND IS AVAILABLE ) on IRS where is my refund page.... What does that mean 

They are still processing your return.  You just have to keep waiting.