Don't ever buy through Makro online

I bought a keysafe through MAKRO online - the website had do specific details on size or dimensions. When it arrived, it turns out the item is useless, it is too small and does not even fir a key and gate remote. So I try and return it and I get told I can't return it as it is through "Market place and I have to deal with a call center. Despite the fact that all documentation, invoice, email, etc. is provided by Makro and Makro branded.