Just for the record and for people who will found this thread in the future... end of the story
Seriously, modchipcentral's staff is really really stupid. Just to add a precision that will have his importance now before moving on, the answer I got about the "wrong name stuff" is because I answered to the previous email I sent them about my Debit Card was not working. I had to do that because they never answered to the new email I sent them with their contact form. It is noted that I explained that in my first email and I gave the new order number.
So, I gave them the name associated to the bank account and got as an answer "sorry there has been no payment received for this". Wait, w00t ? I asked them to verify this and gave them again the new order number. New answer : "ok, we got it. Order proceeded but we're out of stock now, you'll have to wait until Monday".
We're Monday and my order has been shipped. I should get my GW this week.
But seriously, the professionalism of this company is absolutely disastrous. They don't answer to email from their form, they need more than 6 hours to answer to an email sent to "sales@" (when it's not 24h!) and they don't even read your email before answering! If the first guy had read my email he should have see that I changed the order number and thus should have found my payment.
And also, because of their reaction time, I had to wait 10 days to get my GW shipped. I can wait, but seriously...