Bad service

I bought UPS from Showspace and it hasn't been working optimally. I then sent email to enquire with no response from them . Eventually called to enquire about the same thing and was told I should have sent email . The very same email that they do not respond to . We are going through loadshedding, I have UPS that doesn't last for 2 hours . They promised to get back to me and they haven't. Bad customer experience, lackluster service , will definitely not buy from them again