No returns for all users of OneCart

I took 2 x Alva Gas Refill Canisters instead of the Alva Butane Canisters so I went to Makro so I can swop them out for the correct canisters and Makro turned be back saying I need to connect with OneCart directly for all returns, refunds or product switches. I went back home and sent OneCart an email on the 18th of Sept and another email on the 4th of October with my order number to *** Clearly no one bothers to check this email address because to date I still have no response from them. I called them last week to follow up on my emails and the lady said Makro was not meant to turn me back so she will investigate and get back to me in which she didn't get back to me so I called them again today. This is the 4th time I am connecting with OneCart about this and they are telling me that they cannot be liable for the items as the error was on my side. Firstly I never asked them to be liable for anything, I was quite upfront that the error was on my side but I am no perfect shopper, I made a error in my shopping cart so now I'm stuck with the items I have no use for because OneCart has no proper return policy. I purchase my monthly groceries of about R4k a month from OneCart, these canisters are R39 each and I did not expect I would get such a terrible service for a lousy R80. I'm quite disgusted by it and have deleted the app. I will be sure to share this review to my online shopping community, this is the worst service I have received in years, I cannot believe OneCart is still operational with the level in which they treat their loyal customers. Shame on you OneCart, Shame on you