Makro is refusing to refund me for items bought online and didn’t receive

I bought a few items, among them there was 24 x5 baby soft toilet and spokies chips which were not delivered. The purchase was made on the 26 the of November and delivery of the other items was the 28th of November. When I call Makro, I’m given different numbers to call and hold for long periods of time with no resolution. Apparently Makro Montague gardens has not processed my refund since they no longer have the items, and I cannot go to the store directly to request my refund because online and in store doesn’t work together. So basically Makro is holding my money hostage.