Dreamworld has apologised to an 81-year-old grandmother after the theme park's debt collectors incorrectly took money from her bank account for months.
Her son says it was a "money grab", as experts warn consumers to be aware of their rights.
Anne Bates says dealing with Dreamworld's debt collectors was far from fun.
She had a unlimited pass to enjoy the theme park with her family, but her son asked to cancel it after the tragedy that killed four people last year.
Since then, son Greg Bates says, they have continuously taken money out of her account, despite the request to cancel their membership.
Anne's bank account was direct debited $3.25 at least seven times over the past five months.
She received several letters from Debit Success, including one on Wednesday.
Under the Dreamworld logo, the company urges her to pay an overdue $13 dollar amount.
"It's appalling, it seems to me like it's a big money grab," Greg says.
Anne says she only visited Dreamworld twice with her family.
Now she's urging others to check their bank statements to make sure the theme park isn't taking any money.
"If they're carrying on like that with me, what would they do to other people?", she said.
Today, after Seven News informed them of Anne's case, Dreamworld said they "apologised for any inconvenience".
"We have immediately taken steps to ensure the membership costs incurred are refunded in full to Mrs Bates," they said in a statement.
"Before you pass over any of those payment details, make sure you fully understand and fully read those Terms and Conditions," Office of Fair Trading spokesperson Ronni Browning said.