Use your cellphone to call your work phone and have loud conversations. Throw in the “I’ll get right on it” “time lagega boss but but I think I can manage” to add the extra nuance of busy-work.
Hang up the phone and follow it up with a loud sigh. Go back to reading redditt or online shopping, because everyone now knows you are extremely busy and will not come over to disturb you.
Alternatively, you could head out for an “Important Meeting” (i.e. 10 minutes of Nandoo walk) and get rained in dope-ass cash rewards! No pressure, totally your call, but really…