What additional information would you like me to provide? My questions are as follows:

What happened in QB when BDC voided the payment?

What steps do I take in QB related to the refund of the bill amount that BDC deposited back into my bank account? 

When BDC refunded my bank account was there a transaction within BDC that will sync into QB to record the refund automatically?

Since I already completed the reconciliation for my bank account, exactly what steps do I have to follow in QB to address the discrepancy.

What happens in QB when I reprocess the bill in BDC? 

Honestly, it would be really helpful if someone could outline step by step everything that happens when BDC voids a payment. What happens exactly within BDC, what happens exactly within QB and then what steps need to be taken both in BDC and QB to fix it.