I have fiber broadband 500 and have noticed that in the daytime speed test is around 400mb but come the night time it's dropping to 60 70 mb are BT throttling down the speed at night. If so who do I contact to find out as this should not be happening.
BT do not throttle any speeds but more like just a lot of customers using the internet at the same peak time
You do not have a dedicated line.
Speed will vary as you are sharing a 2.5Gb fibre connection with 31 other users, so you will only get the full speed if less customers are using their connection.
How do you know i don't have a Well what happened to the guarantee that I should receive 500mb all the time then
The guarantee applies to connection speed to your hub/router not your download speed to a device