Hi neesh19,
I'd be concerned about the entire plant too, something may be going on at root level. Both of the mature leaves on your Hoya macrophylla appear a bit puckered, which makes me wonder if the stems may not be taking up sufficient moisture. The black spots on the one leaf may be the beginnings of a fungal issue which could have occurred while it was wrapped and packed in a box during transit. The size of the pot looks right for the size of the plant but the soil appears a bit dense and not conducive to a healthy Hoya but perhaps that's just the camera lighting and/or my old eyes.
Many commercial growers use a moisture retentive soil because the plants spend time enclosed in trucks for transport to garden centers around the country. When plants are packed for mail shipment, they are usually in moist soil and wrapped in paper. Those moist, humid conditions can also cause issues. I got a
Wax Plant (Hoya macrophylla 'Variegata') 4 months ago and had to repot it upon arrival because the mix it was growing in was very dense and water retentive. I've been growing Hoyas for more than 15 years and learned from a Hoya nursery in Hawaii that this genera of plants require a light, chunky mix that offers good aeration at root level and proper drainage. For many years now I've been using a mixture of potting soil with a good amount of orchid bark mix and perlite added, which makes for a light, airy medium that Hoyas love.
I'd advise keeping a close eye on it and continue trying to contact the vendor. I'd also send photos to the vendor so that they can see the condition of the plant.
