This is a BT residential customer to customer forum. Your post does not go to BT. The only BT staff are the forum moderators who do not necessarily read all the posts.
If you want to complain to BT you will need to go through their complaints procedure.
If you would like some help to try and establish what the problem is with your connection you will need to supply some information.
Can you run this checker and post back a screen shot of the results. Make sure you delete your phone number before posting.
and use this speed tester then scroll down the page and carry out the further diagnostics and post back a screen shot of all the results including your IP profile for up and down. This test must be done with a wired connection.
If you are using a Homehub 5 can you post the stats from 1-12 by logging onto the Homehub management pages then troubleshooting > helpdesk. http://bthomehub.home/
If you are using the Smart Hub, (Homehub 6) can you go to hub manager then advanced then technical log and post the stats. http://bthomehub.home/
Can you check to see if there is any noise on your phone. Dial 17070 and select option 2, there should be no noise between the announcements.