Day Trader’s Weekend Aftermarket Lounge 26-28 June 2020, page-193

you are plainly wrong and have never filled in a tax return

your words,

you paid $42.00 for petrol and chocolate

you did it twice, so you paid $4.00 total for chocolate

you got $3.00 back from the chocolates

you cant write off the chocolates that you got for free, the tax system just wont allow it

$4.00 less $3.00 means you are out of pocket

it's that simple