This could be a candidate for a class action suit.

Money sent wrongly to an Mpesa number should be refunded fully, whether that number has a mobile loan or not. It's unfair for Mpesa to withhold money and ideally 'Force' the customer to pay a loan for an unknown third party simply because they made a mistake of sending money to the wrong number.  This is an unfair loan recovery strategy, built on the idea that Safaricom is too big to be accountable to small consumers.

Maybe what Safaricom should do is to create a negative balance on the wrong numbers account such that anytime money Hits the account, it is forwarded to the person whose money they forcefully acquired to repay the negative fuliza (overdraft) balance.