Offering a 10% discount, then at the counter if you don’t register they don’t give the 10%.
Please be careful in this diesel shop they do not tell you that you have to register for the discount until you are at the checkout.
For me this was very worrying as I did not want to give my name, they only give an explanation at the checkout after paying without the discount. The staff argued with me about the 10% discount which they offered without telling you that they have to register first.
For this I would recommend you taking care in the shop.