Worst after sales support ever - impossible to return anything if there is an issue

Three weeks later still waiting a response on my return. They incorrectly advertised a home gym. After I logged my initial request I only recieved a response after a week when I complained on social media. It's now two more week and no responses since then. How is a company like this able to operate? You can't phone them. They might appear to have good deals sometimes, but it certainly isn't worth it if you need any support thereafter, they really don't care.