This is:

SMS comes from an unknown number "the amount of 100 rubles in the account, blabla..."
After half an hour from the same number, said, wrong, return the money.

I send "the amount received in the account of 1000 rubles, blabla..."
In five minutes, I write the message, I was wrong, return the delivery to this number.

When the answer goes in the spirit (if censored) "yes it-Madrid, what all the smart
____________

And the next time for a SMS to this number you will be removed from the account 200 rubles, so that you don't get smart.