If you have sold me an item and I've paid for it using M-Pesa, and you have issued me a sales receipt (I hope) then I believe if I reverse that payment, it amounts to FRAUD and you have the right to take legal action against me. M-Pesa is being operated within the laws of the land. It's just a money transfer method.

I have another case to compare: I have a Credit Card with a local bank and every time I perform a transaction, I get an SMS (within 5 minutes) informing me about the same transaction and instructing me to call a certain number (where I can block the payment) suppose the transaction wasn't by me. Now, if I go to Nakumatt or any shop, buy staff, and call the said number to block payment, does that make this Credit Card service less than ideal?

The use of "ideal" in this context worries me!

To me, both cases are ideal. Why should one be reversing payment for goods he'd holding in his custody, plus the proof of purchase (receipt)? Isn't that stealing?