I have exact same problem, I thought maybe it was due to me not switching my router off but it seems that is not the case. My router reports the following:
Downstream Rate : 8128 Kbps
Upstream Rate : 448 Kbp
My download speed is 240k/sec & upload speed atm is 45k/sec
It has been 2 days, but I cant see how it will magically fix itslef tbh, I would call f2s but I rekon they will give me some silly response which wil anger me further as I know I will have to queue for 30 or so mins before anyone even answers the fone! Was happy seeing my downstream rate at 8128 but now its just a joke, wait 1 week for line to be regraded and now by the seems of it another week or so before my line can actually operate at the speed, I bet i'm charged for the max service from the day it regraded tho..
edit: well I phoned them to be told the generic "wait 3 days answer", so if it aint changed 2moro I gonna have to start getting arsey with them. Getting really annoyed now, waited long enough for this bloody "max" connection.