Double charged for parking with no resolution from rude customer service agent

Don't download this app. Upon entry to a mall the camera did not recognize my number plate and I was not promoted at all. Paid for parking in the normal fashion and then received a notification stating my account was debited for the parking fee again (this time with an additional admin fee charge from admyt).

Tried for 2 days to get a refund and was told I can only get one if I send my banking details via email. Customer service was not helpful and insisted that I share banking details despite this being an error on their side. Staff very rude and snappy.