Walmart is reportedly enhancing its pay-by-bank offering via a partnership with Fiserv.The retailer began offering pay-by-bank with Walmart Pay earlier this year, Bloomberg reported Thursday (Sept. 19). But those transactions, processed through the Automated Clearing House, typically took three days to finalize.Under the new system, customers who make pay-by-bank transactions will see the purchase show up in their bank account balance right away, with Walmart receiving the funds instantly, the report said.J ...