Bad customer service

I bought a bath tap from CTM matsapha Eswatini along with other material worth R10k, it was unfortunate that the tap was not the correct one & tried to return it to which I was told I couldn’t, do a return because I had already opened it . I’m currently sitting with a tap that I don’t know what to do with because Mr Duress the manager refuses to do an exchange or refund… as if that was not enough he also refused to have a conversation with me, turns out as I hear that’s just how he treats customers… I never had a problem returning goods before & this is not a good look for CTM … ad