If one collected clothing for a person that was in need of clothing, but that person has seemed to leave town, and the collector hasn’t been able to contact the ani in a long time, can the clothing be given to another charity?
Answer:
In principle the clothing should be given back to the people who donated it.
If this is not practical, or involves a financial loss that makes it not worthwhile, the clothing should be donated to another needy person; a case should be found that is as similar as possible to the original case.
Best wishes.
Sources:
See Shulchan Aruch, Yoreh De’ah 253, citing a dispute among rishonim and ruling that the money should be given back to donors; however, where this is not practical the Rosh (32:6) rules that the donations should be used for as close a purpose as possible to the original. See also Shut Maharsham 3:52. For more details see here.