This is the message I got yesterday and they are yet to reverse my money. Ni system inashida ama they have decided to fleece us.
Failed: Failed.Transfer to Mpesa account 25472****** may or may not be successful due to a delay with our Third Party System. If NOT complete, transaction will be reversed to your account… We are not able to complete the transaction at the moment. Please try again later.
If the money didn’t reach the intended recipient it will be reversed eventually.
I once got a reversal from mpesa after 4 days. I had sent money to a number that was no longer active.