Obi, are you using plusnet for your phone and broadband?Is the line rental included? which package are you using? tell me everything...
BT might not be the cheapest but at least they know what they are doing when you need service beyond making a phone call and paying your bill. It's tempting to save a few quid but be warned if you have any problems you are no longer a BT customer.
I ummed and ahhed for a bit and ended up going with BT. I went for option 3 for t'internet and got a free upgrade to option 2 for calls. Free evening and weekend calls, and upto 8mb broadband. Got a free wireless hub and a smart phone, all in all i'm chuffed to bits. Costs me about 34 squid a month all in.