Family Dollar complaint: Return

Bought a charger for my phone took it out the store doesn’t work. I asked to return it and the cashier told me that I opened it and it was not returnable no were around the display does it say that it is not returnable if you opened it up I am not trying to be a ass but if I saw something like that I sure would have had sure before I opened it up. I am over 70 Miles from my house and was hoping that family dollar would have been able to help me out. Your employees could not help me as to why they showed me something that was so small about the return policy that was no were visible or legible all I want is to return because it doesn’t work out with my phone never plugged it into anything .I really appreciate someone getting back to me and explain why they don’t have this return policy were the phone chargers are and visible. Please call or contact me at [email protected] or 7068327424.I would really hate to put your stores on do not shop for this but I don’t think it will happen if you can tell me why your stores don’t post the return policy around the chargers