I'm having the same problem. I used the promo code when I signed up. The promotions page only mentions free spins upon deposit (more specifically, 100 free spins on Lady Wolf Moon if you make a qualifying deposit, not 10), nothing about getting 10 spins anywhere that I can see, and going to the game does not kick the 10 spins into gear (as is the case with most casinos that offer free spins after you verify your email).
Please be informed that you may have confused the bonuses.
For example 10-20 free spins are usually given out for a simple registration from the promo code as a goodwill gesture and not anyhow connected to the 100 spins bonus.
Also you have a first deposit bonus:
https://vave.com/promotions/first-deposit-casino In the bonus T&C you can see the following information regarding the spins: First deposit free spins are added as a set of 50 per day for 2 days, amounting to 100 free spins in total. The first 50 free spins are added immediately after a successful activation of the bonus. The next 50 free spins are added in 24 hours.
And if for somewhat reason bonus (and/or bonus-spins) were not added, we kindly ask you to contact our support which is available 24/7:
https://vave.com/help/contacts