When the public radio station in Detroit canceled some local music shows and replaced them with nationally syndicated talk and news programs, it probably expected some complaints from listeners. What it got was a lawsuit asking for their pledge money back. A group of listeners to WDET-FM in Detroit filed a class-action lawsuit against the station on Dec. 19, claiming fraud and breach of contract. The Detroit Free Press reported that seven plaintiffs filed for damages after contributing to the station\'s last on-air fund-raising pledge drive, which ended in October. Station managers announced the new schedule on Dec. 13. The listeners claim that they were tricked into contributing money for programs that the station already planned to cancel. \"They took our money six weeks before they made the changes,\" said Dan Sordyl, a member of the committee for SaveDetroitRadio.com, a Web site started by disgruntled listeners after WDET\'s announcement. Mr. Sordyl says that he is trying to negotiate a compromise with WDET or Wayne State University , which owns the station. Like other public radio stations, WDET depends on private funds for the bulk of its operating budget; in WDET\'s case, about 90 percent comes from the private sector. Listeners are regularly entreated to donate through on-air pledge drives, and this active solicitation has the side effect of increasing audience interest in, and response to, programming decisions. A similar lawsuit in New Mexico in 1987 resulted in a station there calling public hearings before making further programming changes. \"There was no relationship between the timing of the announcement and our fall fund drive,\" said Michael Coleman, the general manager of WDET. He would not comment on the lawsuit, but noted that the changes reversed previous programming decisions that had replaced some national staples like \"Fresh Air\" and \"Car Talk\" with locally produced music shows. The new schedule restores and increases the amount of programming that comes from National Public Radio.