Silver Lining Gumboots still not delivered after 3 weeks

Placed an order for gumboots on the 27th of December 2021. Today is the 20th of January 2022 and they still have not arrived. Silver lining gumboots are blaming the couriers - Fastway. Even if it is a courier issue, this should not be my problem to solve or chase up, and it should not take more than three weeks to receive an item that was ordered online from a local supplier. We live in a main suburb in Cape Town where we get deliveries all the time with no issues: Checkers, Takealot, Mr D - never an issue.