Thanks William for your comments. Yes it is a bit of an odd one and I suspect it wonít last? Freebies are great of course. Anyway weíll see. I just checked my My BT app and yes it definitely says BT Infinity 1 up to 52 Mbps.
Found this in my event log, not sure if thatís when the speed increased but it is 23 hours DSL Uptime in 2 minutes so that would tally.
15:31:08, 27 Sep.
dsl:VDSL link Up: Down Rate=58700Kbps, Up Rate=16767Kbps, SNR Margin Down=0.00dB, SNR Margin Up=6.00dB
BT Infinity 1 - 55/10 sync with approx. 51 down /9 up