I need to change my VOIP service to someone else - please any suggestions

Been with them for about 3 years. My phone lines are unclear (they blame my vibe router/internet), the extensions dont always ring, the and apps always have problems. Support is available though! At a cost of R150 to change your password or any other service that you could have accidently assumed you would get if you paid for a service. My issue is that the time i have to call in, a lot of the times its because of some circumstance that we had no control over and their system needs a reset.

I am a business owner. I dont have time to bang my head against a wall asking for the service that we paid for (a working voip system)

We are happy to get all the new equiptment, so that the quality to our clients is not impaired in this way