This is normal, IRCC takes a long time to acknowledge it. If you sent a document, which was requested or that you wanted to add, you may not even hear back from them. If you raised a CSE asking a query, then you will get a response in 15-20 days.
The best way to know if your document or the request was taken on second is GCMS. In the GCMS all incoming and outgoing correspondences are recorded. This gives you peace of mind.
You can also raise another CSE and wait, or try calling IRCC