编辑同志:村里从1998年秋开始,无条件地把邻队的土地给我承包种粮,并把这块田确认为我的承包田,写到承包卡上,承诺30年不变。近来邻队要求讨回土地,村里想让我把地还给他们,我觉得自己的利益受到了侵害。请问:这30年不变的合同权卡是否有效?我能否不还?如果一定要还,我能否向村里讨回我另外20多年的合同损失? Editor’s Comrade: In the village since the autumn of 1998, the land of the neighboring team was unconditionally contracted for grain contracting and the field was confirmed as my contracted field. It was written onto the contract card and promised to remain unchanged for 30 years. Recently, the neighboring team asked to get back the land. The village wanted me to return it to them. I think my own interests have been violated. Excuse me: Will this 30-year contract right card be valid? Can I not return it? If I have to, can I get back to the village for my other 20-year contract losses?