Your account is scheduled for full update every 35 days. If you signed up 15 days ago, that would mean that you have 20 days before you're due for an update. By law, the credit reporting agencies have 30 days to investigate and respond to any disputes they receive. So each round of disputes is every 30 days. Keep in mind, the credit reporting agencies are receiving thousands of disputes on a daily basis, so it takes time.
Credit restoration is a process that requires giving creditors and collection agencies the allotted amount of time to fully update your report. If this process is interrupted in mid-dispute by further inquiry, providing additional information, etc. the time frame to complete the investigation can be extended which will further delay the improvement process. Obviously, this is something we all would prefer to avoid.