On a plus side for ECP, I have a friend who works there, he ordered a set of rear pads and discs for my previous Alfa, the GT, all fitted perfectly first time.
And the whole lot cost me £35.
Maybe its down to the person you get to order the parts?
My first question to the OP is who specified which specific pads and discs you wanted/needed from ECP? Was it you or them?
The reason I ask is that when I put my wife's 159Ti (2.0 Jtdm) reg number into their website, it gave the brakes for a 2.0 Jtdm but NOT the Ti version as the Ti has Brembo front calipers.
Therefore, if you just relied on them to tell you which were the correct discs and pads they may well have been wrong. The only way I could get the right front discs and pads was to tell the website I had a 2.4 or 3.2 as these have the Brembo calipers with the larger discs.
I then mistakenly ordered rear discs and pads for a 2.4 as well, little knowing that the 2.0 has smaller rear discs! I just took them back in to ECP and changed them for the right ones.
As for Pagid discs and pads, I have a VW Touareg (also with Brembo calipers and 330mm discs as it happens). I bought some Pagid discs and pads for that last year as they seemed a reasonable price without being cheap and from what others on the Touareg forum told me Pagid were the OEM supplier anyway. Sure enough, when I took the old pads out they had VW stamped on them but also Pagid!
I have been very impressed with the Pagid discs and pads on my Touareg. It's a heavy car but with 260bhp it's not slow so stopping it is no mean feat. I've never had to press the brake pedal that hard - they just bite and work really well even from high speed. Plus, with the painted coating, they haven't gone all horrible and rusty either.
I have therefore bought a full set of Pagid discs and pads for the 159.
When I took the front wheel off to check the pad retaining pins on the 159 recently, I found there wasn't a disc retaining bolt on the offside front disc at all! I'm guessing it's been like that since new as the car is a 59 reg and is probably on the original discs. I've bought some bolts from Alfa. I don't know yet if the (correct) Pagid discs are recessed or not but will check tonight. My guess is though that if they aren't then the back of the wheel has a recess to accomodate anyway.
EDIT: Just noticed that if you select a 2.4 159 (or a 1.9 for that matter), it gives 2 different brake pads. One with 1 wear sensor and one with 2 wear sensors (but these are for "Date to 200712").
Sounds like a simple case of being given/asking for the wrong pads/discs. You can hardly blame Pagid for that.