to be fair BT support has actually been very good when we have needed them, every year when our line has a brain fart..
it's going again now, think the cabling is degrading one twisted pair at a time..
Ditto, we moved in and our line was poor (<1mb on ADSL), they came out on a Saturday morning (with 48 hours notice) and replaced the copper line and instantly was getting 13mb. Not had any issues since.
Been with BT for the last 15 years or so and very rare to get any issues except getting support to understand sometimes, One thing that works for me is to get put through to the fault line which is in Scotland, they normally are happy to help and marginally better to understand