Is the sample of dates I took considered permissible, especially after the worker said, "Don't let anyone see you, and don't let the supervisor see you," and does my sister taking from it without my knowledge affect its ruling?

If the association's regulations do not permit taking this sample, you must return it to the association. If you are unable to do so, then donate it to the poor and needy, and neither you nor your relatives should benefit from any part of it. If any of it is damaged, return an equivalent amount to the association or donate it to the poor and needy if you are unable to return it.