Why showing only 3 Conversions?

Hi Guys,

Issue is in my phone call conversion tracking. The total number of calls made by visitor is 8 but in conversion that is showing only 3 conversion. I had set phone call conversion time 30 sec. , So in my point of view adwords should show 7 conversion. Why this is happening ?

1. After 3-4 days they are still showing only 3 conversion. So i think that is not data refresh issue.2. We configure to track all conversions. So that is also not a issue.Please let me other regions why this happening ?

Thanks,

Pawas