Your Hoya could be either Hoya verticillata, parasitica or acuta and many people claim that these species are all synonymous. Hoya verticillata would be the proper accepted name and this species can have different coloured flowers and leaves with markings, veins, no visible veins, a visible central vein or midrib as in your plant and varying leaf thicknesses. Mike

Oh good, glad that's correct. I was going to suggest the ruschifolia name, as I have this, but wasn't sure & I knew Denise will know as I've had some from her yrs. ago. I believe my current one is from GreenToes, if you knew him when he was posting here. Before you return it, pls know that it's an easy grower & has charming tiny white flowers btwn the leaves. Maybe consider keeping it? It takes the same care as Hoyas. But I do know what you mean abt H curtisii, which I've been trying to replace for a while myself. Glad to solve your mystery.

The bottom picture looks like burtoniae but the top? I don't know. The small burtoniae I have the leaves are more rounded. Hopefully some others will be chiming in with a more expert opinion. Whatever it is, it sure looks healthy. You're doing everything right apparently.

Yep, Australis and a left foot!