Dell XPS M1330: failed motherboard, power adapter & customer service

UPDATE SUNDAY:
After it took forty minutes and five emails between me & Friday's extra special Dell helper, I have called the external contractor three times and they still have no record of my existence. I am currently on the phone to Dell. I have now spoken to SIX people over the course of the last 32 minutes. SWEET MOTHER OF GOD they've just put me through to Latitude support not XPS support. Okay being put through to the SEVENTH person...

Right the seventh person was a beacon of sanity & helpfulness. And would you believe it? Mr Condescension from Friday HAD GIVE ME THE WRONG NUMBER after all. So it's no wonder the external contractor had no record of me - because it was the wrong contractor. F**KWIT.

I have just spent 52 minutes on the phone.

I have just called the external contractor who have told me I cannot arrange a time for the technician. They will page him & see when he is available. When I said when shall I call back?, she replied, "Please call us back after some time." Riiiiggghht. Helpful, that.

Oh & did I mention that somehow Dell have arbitrarily decided to swap my warranty to the UK which is just adding another layer of horror/confusion to the whole ghastly affair? I bought my laptop through Dell America online, had it delivered to New York, have had it fixed three times in NY & have never requested a warranty change.

I really want to cry right now. What upsets me more than anything else is that the problems are all of Dell's making. I am paying in time and in money for their substandard hardware and incompetent technical & customer support. The only ray of light in the darkness is their Social Media department who are like manna from heaven, as they return emails (the guy quoted above never returned my Tuesday email, resulting in my Friday phone call), facilitate repairs, and cut through the nightmares.

Oh and regarding that warranty: it might read Complete Care comprehensive warranty & service contract including Next Day/Weekend/Night On Site Technical support, but it's a Complete Crock . They don't keep parts in stock so they can never come next day as the parts have to be ordered. (Because all that ever goes wrong with an XPSM1330 is that Dell use crappy parts - hello NVIDIA - which breakdown & have to be continually replaced - hello second motherboard & power adapter in three months). And the parts despatching people aren't open over the weekend, so forget about the weekend onsite support.

PS if you've come here through Google, this site is a catalogue of errors with the XPS M1330. It seems I am not alone in having had two failed power adapters, a replacement screen & two replacement motherboards - within a period of four months.

UPDATE (Tuesday):
The Dell tech cldn't come on Monday as the parts didn't arrive in time - quelle surprise, but a very charming man from Unisys arrived an hour early (hurrah!) today, and dismantled my laptop, replacing the motherboard. Unfortunately, Dell hadn't ordered me a new adapter, so he said, so I am STILL awaiting the delivery. They promise via FEDEX tomorrow. We shall see. I fly to London on Thursday and there will be ill humour if it has not arrived by then.