Disgusting customer service

I placed an order with Mac online on Thursday last week I wanted to ask them to change the colour from d for danger to ruby woo I was told this is not possible and I will have to accept the order as is and lodge a return so they can refund me but I would have lost out on the promotion why can’t they change the colour cause the order is still in their hands and let me not get started on the agent I spoke to over WhatsApp the rudeness is appalling (Mille). I hope they change their ways of doing things cause this is how customers are lost I am a first time customer but I will not be returning again . We are also not permitted to cancel orders