I think ACCA should offer a script-review service which, whilst not returning your script to you, gives you feedback on your answers in the exam.
CIMA offers this service to candidates scoring 40 – 49, so I don’t see why ACCA cannot offer this as well. It’s not cheap mind you – it’s currently £160 per paper, so no doubt it would be same or higher with ACCA and probably out of the reach of many candidates.