The phrase "gat one face" is actually a phonetic transcription of a Scottish phrase "get wan fiz" which means "get one's own face" or "mind your own business". In this dialect, the "g" sound is pronounced as a "y" or "j" sound, represented as /dʒ/. The "t" sound in "get" is pronounced with aspiration, represented as /ɡɛtʰ/. And the phrase is written in the Scottish dialectical spelling of "wan fiz" instead of the more common "own face".