Your phone got looked because SEUS rebranded it with branded firmware. You can easily patch unlock and debrand your phone if you don't want the branded firmware. However, if you do patch unlock, you need to unlock the phone each time you upgrade the firmware.
Remove SIM-lock patch generator
As for debrand, just download the firmware files for your phone. I prefer to use CID52 over CID53. Then use XS++ to flash it.
Remember to debrand first, then unlock. If it's CID53, I can't help you there but search around the forums.