travelin cat is right. Additionally if same phone is used on listings it can cause many to merge together so for example 3 of the listings may merge together into 1.
Also if it's not against the guidelines here, can you tell us what industry?
Because, if it's a service area business like a plumber or carpet cleaner there are 2 potential issues.
1) It's a violation to set up multiple locations just to rank in the areas you service. Google will often delete or merge them. (Sometimes SABs try to rank by setting up listings at employees homes or friends, just to try to rank in other cities)
2) If it's a service area business and if you didn't hide address on the listings, that's a newer violation and Google is deleting listings left and right that violate.
There are a bunch of other potential reasons but I'd be shooting in the dark to guess without specifics.
If you need help you can post all the details at the Google and your Business forum and get help there too.