Somebody 'shadowing' my network credentials

After close monitoring of my router's behavior - here is my observation

1. My laptop does not have an Ethernet Port - so connection is only thru wi-fi

2. There is a lag between my changing the network name / password and it showing up in available networks

3. My earlier network name persisted even after I reset the router after changing the name

4. There is no other device connected on the network and the only access would be thru SHM (or backend)

Somebody with access from ATT's side (legitimate or illegitimate) is lurking in the neighborhood. 

If it happens to me, it is happening to others also. 

My 'situation' allows me to make these observations while this is undetected in most other cases.

AT&T has to take ownership of the issue and address it.