When they say they've boosted your connection all they've done is change the speed/stability ratio/settings.
The higher the speed the less stable the connection can be which leads to drop outs.
You can go into your profile yourself and adjust these settings. The settings can be changed to have lower ping, or faster upload etc, there's normally about 6 different options to choose from. The stability at higher speeds usually depends on the quality of the copper wiring.
So the max speed down/up setting can lead to drop outs so often ISPs will set it up so you don't have drop out issues which often means a slower speed
