Nestra

From Tardis Wiki, the free Doctor Who reference

Nestra was a holiday planet run by the Thetrans.

At one point, vacationers had gone missing. The Sixth Doctor and Janis Carma, a Thetran agent, were sent to investigate. They discovered that the robot responsible for serving the tourists had allowed them to get sick and then refused treatment. The Doctor and Janis stopped this practice. (PROSE: Wish You Were Here)