the missionary who first set down the language had a faulty "s" on his typewriter, so he used "ti" instead

This sounds like the story behind Pago Pago (pronounced Pango Pango). The missionary was faced with a language with a plethora of ng sounds and not enough ns in his type set so he made do with the g. Apparently the g sound was not present in the language and all his ns were used up representing the n sound. Or so the story goes.