Facit was a brand of typewriters made by the company of the same name in Åtvidaberg, Sweden. The poem says so in the second stanza:
Mine is a Swetish Maid
Others are OLIMPYA or ARUSTOCART
RAMINTONG or LOLITEVVI
“Swetish Maid” = “Swedish-made”. The other references are to Olympia-Werke, the “Empire Aristocrat” brand of British Typewriters, Remington and Olivetti.
(Note that I don’t think it makes sense to interpret the poem as being written by the typewriter itself: the typewriter would surely write, “I am a Swetish Maid called FACIT”, not “Mine is”. I interpret the speaker as representing a fictionalized version of the poet.)
There are a couple of puns in the last line: “facit” is Latin for “it makes”, so that “FACIT cry I” implies that the poet blames the typewriter for all the errors: “it makes” them, not me, he says. And “FACIT” sounds like “fuck it”, which expresses the poet’s frustration at the state of the poem.