I have discounts in fuel station. (fuel stations/the fuel station).

In Spain there are malls called “El Corte Inglés”, and these one have their own card.  This is not for using at an ATM, but is for for to buying (OR making purchases) into its stores.

There are fuel stations called “Repsol”, and these one accept it the card from “El Corte Ingés”.

I fill the fuel department tank with my card from “El Corte Inglés”, and each every three months they provide me* discounts for to buy** in the malls again.

*provide me with OR *give me

**for buying / for using

With this operations win they both.*

*With this operation they both win.  However, it sounds more natural to say: "Through this method, they both win."

I drive a lot kilometers each month, and with this it I win too.*

*in this way I gain too.

Well done, José María!  A great piece of writing which I enjoyed.  That store card certainly sounds useful!

The Spanish verb ganar can mean different things in English - to earn, to win, to gain.  In this sense the word would be 'gain'.  Win = a prize, earn = pay, a salary etc.

Congratulations and keep up the good work!

Leigh

I have discounts in fuel station.

In Spain, there are malls called “El Corte Inglés.” These malls have their own card, which is not for use at the ATM, it is for purchasing in its stores.
There are fuel stations called “Repsol”, and these accept the card from “El Corte Ingés.” I fill the fuel tank with my card from “El Corte Inglés”, and every three months they provide me discounts for buying in the malls again.
With this operation, they both win.
I drive a lot of kilometers each month, and with this, I win too.

Great job!