Bugs in bed and on the windowsill

Bugs in bed and on the windowsill

Observation - Bugs in bed and on the windowsill. Description: The big black ones are 1mm in size. They have some sort of white pattern on their backs if you look very closely at them. They have six legs, anteni and they crawl and don't jump. They are really hard to kill due to their hard shell-like backs. I find t

The big black ones are 1mm in size. They have some sort of white pattern on their backs if you look very closely at them. They have six legs, anteni and they crawl and don't jump. They are really hard to kill due to their hard shell-like backs.
I find them in my bed and I am covered in small, itchy bites.
The young ones are so hard to see but they can be seen on the windowsill well (pic 2).
I've tried bed bug treatment (spray and powder) thinking they are bed bugs but they don't seem to be affected by it and keep coming back. Please help me find out what they are!