Hotels and alternatives
Nothing. Go back to Matmata (10 km) for the night.
Restaurants and alternatives
There is a café at the summit in the village, but this will not do too much in terms of food.
Nothing. It is best to do this in Gabes, if your hotel in Matmata will not help you with changing money.
There are some few buses doing the stretch between Matmata and Tamezret, but this can involve some waiting. It is best to arrange for your own transport, preferrably a rented car or a rented taxi (with driver, of course) in Gabes.