What happened to Nextiva & help.

I owne a small restaurant with 5 phones. We were looking for a system to cut down on spam calls ant to route catering and event calls to managers mailboxes. My partner went with nextiva based on great reviews and a good previous experience. We have had it for 2 weeks and its absolutely horrible. Only 2 of the 5 phones are receiving calls. When we spend 3 hours on the line with the first level tec support and they cant solve it it takes 3 days for the second level to call and they are also no help or disconnect. Does anyone have a good recommendation on a basic service that is user friendly. Thanks