Failure to do a reversal on my ecocash transfer

On the 23rd of May 2015 one of my clients Rumbidzai Kanyanda made a transfer of $24 by mistake to a wrong number *** which is owned by Isabel Madzima instead of *** ,Rumbidzai contacted Econet concerning this issue and they promised to assist her in getting the money back and they never did. Rumbidzai was settling an account with me therefore because of this i have not been able to get my money which i believe til today is still with econet.i am sure if econet really wanted to assist me they could have done so long ago ,its almost a month and i still havent recieved my money.Econet put this system in place and am sure they are well awre that such incidences are bound to happen especially if they continue to issue out almost identical sim cards.Please help me get my money back.