Well, after contacting support because my download speed was 1-2Mbps I had several calls over the last 2 days:
(call 1) don't know the precise cause of issue but we're working on it and will have it fixed in 2 days
(call 2) we know there is a network issue and it'll be solved by 2nd March
(call 3 to different dept) sounds like there's something more fundamental wrong than network issues for it to be so low - call tech dept again
(call 4 to tech dept) We're waiting for new servers to fix the network issue in KT area. Give it 15 mins and I'll change something our end to improve your performance meanwhile.
Now my performance went from 1-2Mbps to 35-70Mbps!!!! Happy days. Just wish I'd reached this chap the 1st time.
Glad you got a result Paul. It can be a lottery as to whether you get a decent tech or just some gormless idiot reading from scripts.
I'm also in the KT area and more recently have been suffering from over-utilisation in the evenings when my usual 76mbps drops to single figures. Very frustrating.