"I called computer share and the person told me as long as the...

"I called computer share and the person told me as long as the money is received by tomorrow morning, it will recorded as being paid today. Called me bank as well and their BPAY file closes at 6pm, so hopefully I shall be safe."

This is how BPAY works, BPAY is not interactive system it run batch file, each time someone BPAY it get recorded the time and date you pay, it then collect all those payment and run them at some point during the business day usually late at night or end of the business day.

BPAY done over the weekend it schedule for the next business day ...with SPP you can pay as late as the closing date..
just make sure it is before 5pm on the closing date...

the receiver will notice that you pay before the closing date and you all good to go...

when they say it close by 5pm 03/06 as long as that get recorded on BPAY system you are safe and they usually wait a day or two for all the payment to come in due to the batch nature of BPAY before they start allocating shares ...

Bottom line use your banks and make you run BPAY by no later than 5pm closing date and you are safe even on the closing day.