Alans suggestion of DLM > IST > LHR then the bus is pretty solid.
The only other suggestion I can make is to fly TC from Antalya to Manchester on the 10th, leaves at 15:30 and gets in to Manchester at 17:10. There's a FlyBe flight from Manchester to Exeter that leaves at 20:30 getting in to Exeter at 21:35. If you cant get picked up, its about £45 in a taxi to Torquay - be a little more to Paignton.
You may need to play with the dates from Antalya, but the Manchester to Exeter flights seem to be three a day.
JF