Sold a used watch

I was sold an old used watch at Truworths Menlyn. I called HO and they said I must send them an email which I did explaining exactly whay had happened. Menlyn branch manager then contacted me in the morning and asked me of the sales person had shown me the watch my answer was no and she had said she'll ask for more info as she was still investigating to my surprise she calls an he later and says they can't exchange the watch bcz the links have been removed. That's the very reason why I returned it because it was used.i ddnt get any help.im not satisfied with how she conducted her investigation because at the end of the day shes protecting her team .if contacted Truworths HO since last week no response nothing.please help .I need to fight for my rights