Select Menu > Ctrl. panel (or Settings) > Connectivity > Bluetooth.

To block a device from establishing a Bluetooth connection to your device, open the paired devices tab. Select a device you want to block and Options > Block.

If you reject a pairing request from another device, you are asked if you want to block all future connection requests from this device. If you accept the query, the remote device is added to the list of blocked devices.

To unblock a device, open the blocked devices tab, and select Options > Delete. To unblock all blocked devices, select Options > Delete all.