Even with a polite DA letter, sometimes you won't be left alone to go your way in peace. Dave Brown recently posted a series of letters (6.3 MB pdf file) related to his leaving the Encanto, AZ congregation in 1980. It starts with his letter of disassociation, then a letter he received telling him he'd been disfellowshipped in absentia, written to him more than five months after his DA letter, and more than a month after the announcement to the congregation (We thought you should be the last to know!). It continues with his reply to the congregation elders, and eventually to Fred Franz and the rest of the Governing Body. He points out that they had not followed the procedures in the "Pay Attention..." Elder's manual, and that there was no reason to DF him because he already was no part of the congregation. It concludes with several pages of documentation explaining his doctrinal disagreements with the Watchtower.
For a small sample, here's the introduction of his letter to Fred Franz:
Dear Mr. Franz,
The May 15, 1980 Watchtower (page 30) relates the almost unbelievable response one man received when he wrote to hls local Catholic Church to have his name removed from its records: "Under no conditlons can we remove your name from any Baptismal or other Sacramental records. As you know the Catholic Church is the one true Church founded by Jesus (Matt 16) and to so remove your name would be a sin against the Holy Spirit." Surely, such an attitude by that Catholic Church is hypocritlcal and preposterous. Due to recent developments I feel compelled to ask if a similar attitude is to be encouraged among Jehovah's Witnesses? I do not believe you think so.