Unacceptable turn around time

Payment instruction given on Thursday 17 December 2020, email was received to say insufficient funds ,where a reply was sent showing that funds have come into the account, Friday 18 nothing was done, called business banking and was told my payment will be processed on Monday, called my business manager but there was no response.this is unacceptable as a client I need to constantly cheak my emails as now calls are not made to us.my clients that are awaiting payment are up in arms , what explanation should be given to them...my bank doesn't value my business?