Pick and pays faulty goods terrible service

I bought a power bank at greenstone mall pick and pay which was clearly faulty ( swollen ) . On closer inspection it seems to have been opened before but closed again and put back on the shelve to be sold. Trying to get any satisfactional response from @PicknPay seems to be frustratingly useless until i started to being nice and threaten that ignoring me is only going to aggrevate me even more. I will not be cheated out of my money without it getting nasty. This has been some of the worst customer service I've ever experienced in al long time