I called up BT on the 3rd of July to check about getting broadband, so they said I'd have it on the 25th of July (which was a bit slow but they needed to add the phone line, so that was alright). Not 5 minutes later, I got a text saying they'd (already) delayed it to the 1st of August, taking it up to a month.
On the 1st of August, the engineer announced that he couldn't complete the work, so set a new date for the 17th of August, taking it to 36 days after my original enquiry.
Later that day, I went off for a holiday, where I lost my phone. On the 17th, I waited in all day, having recieved no word from BT whatsoever. When the latest time for an engineer came and went, I called BT, who informed me that they had cancelled the order via text.
No reason was given, and no alternative means of sending the message were used. I called BT to have them reinstate the order, but the date has now been put back to the 6th of September.
While I acknowledge that this may not be the case for a lot of people, I've heard other reports of BT being slow and in some cases, simply unwilling to actually provide the services we pay for.