hi..Thanks for the query..
The black /dark spots that you mention are known an post inflammatory hyper pigmentation ,which is a very common form of pigmentation to remain after any injury/disorder of skin. Waxing/epilation might cause an infection of hair follicles which is a common cause of this spots.The earlier you treat them ,the better are the chances of them lightening.
You can use a topical cream having 2% hydroquinone
once daily on the spots, taking care not to spread it into the surrounding areas.Do this for about a month and see if they lighten.
You can also do few sessions of GLYCOLIC peels on the spots only from a qualified dermatologist
.this help faster exfoliation and lightening of deeper layers of pigmentation.
You must always use a broad spectrum sunscreen with or without the above measures to prevent the spots from darkening by exposure to UV light daily..
You can try Laser
hair reductions ...They are safe for skin and the body..However the choice of Laser depends on the skin type which has to be done by a trained dermatologist.