You don't get sell wands back as they are consumables. Consumables are things that can be traded in game and can be lost (by death, lava, running out of uses or reset ect.). In this case, unlimited does not mean you can't lose it but that it can't be lost due to running out of uses. The only exception to this is if you bought it 7 days or less before the reset. Non-consumables like multipliers/ranks/perks cannot be lost in any of the ways listed previously and so get given back after a reset, unlike consumables like sell/condense wands or crates ect. which don't.
Hope that explains it well enough : )