My dad got the Samsung Galaxy S7 back in May and wanted to SIM unlock it shortly after because he travels a lot due to work. No rooting, just unlocking the phone to use with foreign carriers. At the time, he went to a local store that provided him with a code but it wouldn't work, they told him something along the lines of "this phone is too new and cannot be unlocked yet". I was really busy at the time so I couldn't provide more assistance unfortunately. He phoned Rogers (his phone provider) and was told that they could provide him directly with an unlocking code but he had to wait 3 months from the time of the purchase. He thought that was a much safer way to do it, so he waited.
Fast forward to now, and the code he was given wouldn't work. According to him, even after following the steps in this page from Rogers he gets a message that says "INCORRECT NETWORK UNLOCK ENTERED". He also attempted to get it unlocked at a local store (from the foreign country he's currently working at) to no avail. I believe they even tried a factory reset, and the SIM unlock still wouldn't go through. As time goes by he is getting more frustrated and I don't know how to help since we're in different countries. Is the phone hardlocked after many unsuccessful attempts? Can such a thing occur even after a factory reset? Also, do you think it would be possible to get the phone sent to warranty for this problem?