Apple Music 3 months free

Hello there

Im new with iPhone, when i go to the apple music, it says 3 months free, and i choosed an individual plan, i paid 6.99€ and when i go to account settings and subscription it says next billing 12 August, which the next payment is already next month, and i wanna ask where is the 3 months free? It should be sais Next Billing 12 October.