Mine is the same model, it seems to work fine, Try checking your USB cable or if your micro:Bit is damaged.

I used the cable it came with though

look install scratch link then dont open it as it is already running. In your system tray see if the scratch link button is there. If it isnt, then open the scratch link app in your start menu and go to scratch. enable the extension. make sure the scratch .hex file is already on your microbit

I already returned the micro:bit

It worked for me and I have the Micro:Bit v2.21.