low pressure with Breville coffee machine

This is more of a review than a complaint. I bought a Breville caf? venicia from the vredenburg branch, and returned it because it never sealed at the grouphead. I then requested a refund and bought the Breville Barista Express from them which I personally collected at the bayside mall branch, which is working, but only on single shot. As soon as I use the double option with the double filter, I can't get the pressure to the espresso range. I tried the finest grind, and even bigger dosage. I tamp it down so hard that my fingers hurt, with no results. But when I use the single option with the single filter, the pressure goes straight to the espresso range, on factory settings, and I don't even have to tamp down so hard. This means I can only make one espresso at a time, with a machine that's supposed to deliver more. This is nothing against @home, their service is extremely good and I'm very happy with them. This complaint is directed at the poor quality of Breville, that I paid a huge amount of money for. It really is not worth it, and I wouldn't recommend Breville to anyone.