How long of a validity does the DBD company "lap long" document (house on company name) have for Marriage visa extension at Immigration? Is it one month or 3 months?

Your proof of residence should be current. But unless you change address it does not have to be a new one.

At Phuket they refused one I presented that was over 6 months old, they insisted I got a new one and that it was stamped with a company stamp