What's a good Internet / phone provider in Belgium

I've had Belgian Telecom for several years - prices are competitive and calls can be made to landlines for free to a number of countries. Internet is fast.

However, the service is awful, the phone doesnt work about 10-15% of the time (busy when people call although nobody is on it - and distortion when I call out so I can't hear what people are saying).
What's a good alternative to this company?