Mcdonalds maitland-bad service

Good Afternoon

i recently ordered online from Mcdonalds maitland, requesting that they send a card machine with when delivering my order as i did not have any cash on me.

My order arrived ,somehow when i inserted my card the first time it said error ,second time it went through,I checked my online banking only to see my balance .even though machine said error I was charged twice . I immediatly called the store to inform them and asking how to do I get a refund .

Manager was not very helpful and accused me of lying and demanded a bank statement from me. This is unacceptable as ,the mistake in on their side now they do not want to take responsibility