Review Failure to install steel shed after payment

We paid for a supply and installation of a steel shed in Gaborone Botswana in December 2020, the agreement stipulated that upon final payment,the shed shall be installed within 2 weeks. Covid-19 cross border restrictions aside, the company had failed , 12 months later to deliver: they are extremely arrogant to the extent of now no longer communicating and threatening us to use for defamation should we post bad reviews.We got work permits for their 1 man to come install twice and it's been 1 story after the other.They delivered the materials months later after we posted a review on Google. We have proof of payments,emails and what's app chats to prove all this. We clearly have been scammed, be warned.