I think you are referring to the recent promotion about Mobile Money double Credit. You won't get double credit by simply recharging as usual.

For this offer to work (valid upto 10/10/2012):

1) Register with Qtel Mobile Money - *140#
2) Goto any Qtel machine and load any amount QR50 or above.
3) Recharge your/any other Qtel number with 50 or above from your Mobile Money account (*140#) to get double credit.