2 weekends ago, i went to my regular store, and picked up a new trio of platies, and a trio of swordtails. within a few nights, one of the swordtails died, so i went to get a new one since my water tested fine. when i went up there he told me that he was sorry, and he thinks that someone poisoned his tanks(just a few live bearer ones and tetras mainly) and that in a week i could get another one. i asked if my others should die too, and he told me no, if they were going to they already would have, but they have all died since then except for one of the female platies. do you think i should get an exchange, or should i have to pay for new ones??? just wondering what everyone else thinks.