The Situation

So I trundled along to EBuyer the other day for a DVD Burner to insert into my beloved computer. For those who don't know EBuyer, let me massage their ego for the first and only time. (deep breath) They've got a remarkably good website, selling products with remarkably cheap prices. (there, I did it) £30ish for a DVD Burner and a pack of DVDs wasn't a bad offer, I thought. In fact, it was a cracking one, so I bought it - along with an Epson printer.
Now, I've bought from EBuyer before. Hell, I'd heard a few bad stories before - but they're two a penny these days. The price (and the fact that nothing bad had ever happened to me) lured me in, sat me down with a warm mug of cocoa and persuaded me to part with my hard-earned cash.
I waited. Then, an email from Ebuyer Customer Services (a moniker that seems vaguely ironic now) informing me that my order was being split into two - the first being the printer and the second being the DVD Burner. Odd, I thought, but why the hell shouldn't they, as long as I got everything. The printer came without trouble. And then I waited some more.
And some more.
Eventually, the DVD Burner arrived, minus the DVD pack. I checked my bank account to see if all the money had now come out. Peering closer, I noticed that they had removed the pre-VAT price of the DVD Burner from my first order when they split it - but had then preceded to charge me full VAT-included price on the new second order. I was out of pocket for the princely sum of £5 and had no DVDs. The website had also been modified to erase all trace of the free DVD pack. I found their helpline number and tried calling it.
"Contact Us - it's easy" boasted their help page, a claim that Trading Standards should be keenly aware of. After 30 calls over the next day, I tried in vain to get through to the helpline. Handily, the phone number doesn't just show up as engaged, but connects me to a recorded message (that I pay to listen to) that apologies for all the operators being busy, and would I mind calling later. Calling later? I'VE BEEN TRYING TO, HAVEN'T I?!
After scouring the website again, I found the only other way of contacting them - through an innovation called ENotes. They claim their turnaround for ENotes is seven days, and as this wasn't a bank-breaking matter I was content enough to wait.
However, days passed. Weeks passed. All the while, I was calling their helpdesk at various times, only to get the same apologetic message every time. I sent them a follow up ENote asking where the hell they were, and still no response.
Eventually, after 30 days, I opened up my inbox - and to great excitement saw an Enote response from a lady named Karen. I opened the email, and read the following with incredulity:
"Thank you for contacting our customer care team.

Firstly, please accept our sincere apologies for the time which has elapsed since your eNote was posted.

Due to this timescale we are confident that your query has now been resolved, and so to allow our customer care team to concentrate on current queries, your outstanding eNote has been closed. If this is not the case, or should you feel your query has not been resolved to your satisfaction, your enote can be reopened by logging into your Ebuyer account and selecting the eNote facility.

Once again we apologise for any inconvenience which this delay may have caused."

Looking suspiciously like an automated reply, the email was essentially saying that the ENote had been opened SO LONG that things must have been sorted. The ENote was automatically closed by this elusive "Karen". so, naturally, I reopened the ENote, asking for an answer and noting that they're "probably waiting for me to go away".

So, a summary: they've overcharged me, delivered less than they promised, modified their website to remove the evidence and given me two ways to contact them - neither of which work. Where do I go from here?!