Yeah you've had a narrow escape mate. Personally I have found the reliability and value of their service to be good, but their customer service is appalling.
It took them 7 weeks to install a new line and connect me. It took 4 weeks just for them to give me an engineer appointment to install the line - sod's law it was the only day that nobody was in the house, so I rang to rearrange it - the guy said he'd contact me with the new appointment.
Two days later, I'm at work and my phone rings, the BT engineer is outside the house, here to install the line. Luckily the guy is a nice chap and says he'll come back in half an hour giving me time to rush back.
Engineer installs and checks the line, everything is fine. Rand up Bulldog the next day to ask why my line is not activated (which the BT guy said it was) and to politely enquire why I wasn't told about the engineer coming round. The guy at CS tells me my line is not activated because I am still waiting line installation. As you can imagine, this riled me a little, explained that I saw with my own two eyes that he has - the Bulldog guy seemed not to believe me, but said he would email BT about it, and could I ring back the next day as it should be sorted.
I ring back the next day, as the woman I speak to where the activation is up to. I should have been less surprised when she says "I'm sorry sir, we are still waiting for a BT engineer to come and install your line." Sigh. I explain what has happened so far, and she says she will check with BT and ring me back tomorrow.
Tomorrow comes and goes. I ring up the following day to see why I wasn't contacted. "I'm sorry sir, we are still waiting for a BT engineer to come and install your line." ARGGGGGHHH. I hang up in disgust.
After a calming cuppa I ring again. "I'm sorry sir, we are still waiting for a BT engineer to come and install your line." Ok, I was expecting this, I explain the situation, ask why I wasn't called, the guy gives some pitiful excuse about the system being down. He says he will personally check and ring back within the next two days with an update. I ask him if he actually ring back or if he just cba with me, he reassures me but I make a note of his name anyway (even though I know that their computers have a list of everyone I have dealt with).
The next two days come and go. I give them and extra 2 days since it is the weekend, and ring monday morning. I might add that as I naturally don't have a phone line all this is on my mobile, so isn't free

(got my bill back, £12.74 in total costs!). I decide to head the guy off at the pass and explain the full story to save him the barrage that would inevitably follow me hearing "I'm sorry sir, we are still waiting for a BT engineer to come and install your line" again.
The guy is completely unapologetic, and patronising - he actually said "There, there sir, i'm sure it's all going to be ok" - so I ask to speak to his supervisor. The supervisor seemed to be about the only person there who actually had an idea of what was going on, and explained that the BT engineer had come round independently of Bulldog telling him to, which is why I didn't know about the appointment. BT had sent over the necessary information, so they could now proceed with my activation. I ask how long I should expect this to take. I ask again because I could have sworn he said 28 days. ARGGGGGGGGHHHH.
Fortunately it *only* took 10 days, so we're now happily connected, and I cannot fault the rest of the service, but I will be terminating my contract as soon as this year is up.
I have lodged an offical complaint with Bulldog, but in the month since doing so I have heard jack. I will give them a week or so then am complaining to Ofcom I reckon.
edit: sorry for the rant, but i felt i should warn any potential customers