Personality.co Unauthorized Charge After Test

I recently completed a personality test on the website Personality.co, for which I was charged €1.95 on Monday 23rd via my PostePay card. I accepted this small payment only for the one-time test and I was not informed of, nor did I request or accept, any kind of subscription or recurring service. Despite this, on Tuesday 31st an additional charge of €39.99 was taken from my PostePay account without my authorization and without any prior notice or clear information about a service corresponding to this amount. I consider this charge to be unjustified and not consented to. I have already contacted Personality.com and I am currently still waiting for a response. Through this complaint I request the immediate refund of the €39.99 charged without my authorization and the assurance that no further unauthorized charges will be made to my PostePay card.