Actually, I know IANBU.
The past tense of 'to text' is 'texted,' as the past tense of 'to telephone' is 'telephoned.' It is conjugated as a regular verb, which in English means that one adds 'ed' to the present tense make the simple past tense.
Writing 'text' when you mean 'texted' just makes you look illiterate, and makes my teeth itch. The latter is far more important, obviously 