I want my blazer that I paid for!!!!

I ordered a blazer from this online boutique called Fashion_factoryza on the 6th of October 2021. They sent me their banking details I made a payment on that day but today 3 weeks later I haven’t yet received my parcel. They said it takes 3-7 working days to deliver. Their service is very poor. They keep saying they are doing the follow up. I’m very angry and unhappy with their service. I want them to give me my money back if they are failing to send me my blazer.