If you are using the white Icotera router that brsk installed, please take a look at this article.
So, your fibre was installed, and your internet is active. You were experiencing the correct speeds, but all of a sudden the speeds have dropped. Not to worry! Typically a quick reboot solves this issue.
Simply reboot the two brsk devices that were installed.
You can do this by pressing the power button on each device. Wait 1 minute and then turn each device on again.
Once done, please run a speed test to ensure that your internet is performing as it should.
To find out how to run a speed test, please take a look at this article.
If you are still experiencing slow speeds, please reach out to support via support@brsk.co.uk or 02039 255 299.