I've filled mine at the Pepper Market, Francisco's, Siestas (by the pool) and I can only assume that the new bar outside on the esplanade will fill them too. Oh and the Maya Grill if your eating there.
I really want to pick up one of the big ones when I am there in September. When I was there last December they did not have them. But earlier this year I heard they were back. We shall see.