Can I purchase this phone for full price & then use with a prepaid plan?
I spoke with an ATT retailer who advised they do not sell any smartphones Samsung Galaxy S6 without a contract but I could purchase this phone from Best Buy & they would be able to utilize a sim card for the prepaid monthly plan.
AT&T is in the wrong by telling you that you cannot purchase the phone w/o a contract. They, including Best Buy, can sell the phone to you w/o a contract, but you will have to purchase the phone outright. Meaning you'd have to pay the purchase price of the phone, whatever it may be. You would be looking at several hundred dollars.