Problem  to resolve:  Voice Mail for Chicago Call Group.

We have apparently been getting phones calls that are being sent to voice mail for our office. Apparently we are only receiving a few that are fowarding to vm. Many customer are saying that they are leaving messages on vm but we are for some reason not receiving. We currently have 7 Phones.

Many times the customers that are reaching us are saying that the vm is full. I personally check every morning im in and only see one phone sometimes two phones have messages that I review. Are the routing correct? Are the phones calls being routed to another ext elsewhere? Please check on this to find out if all routing of VM is getting to our office.

Resolution to the problem of voicemail is full

Here are the phone extensions which are listed in our system for Chicago as of 10/7/2015
100
101 main call group
102
103
104
105
106
107
109
135
250
251
252

the main call group 101 attempts to reach the following phones with 10 double rings
101 call group members as of 10/7/2015
251
106
105
135
104
102
101

It then transfers to voice mail for the 101 extension 

To access this extension
click on messages 1 time
click the clear button
enter the extension 101
click the OK button
enter the password 1234
click the OK BUTTON

You can now scroll through the messages and respond as well as delete