I cant create an overwatch account with my new phone number?

I switched in the last week to a new phone number (Germany) and thought about joining overwatch since its free. Well after creating my battle net account, downloading and installing overwatch, the game told me :" This phone number was already used to create an overwatch account - contact the support or get a new phone number".
Well I did contacted the support and told them that my pre paid number was already used from someone else but that this is actually my NEW number (I got it this month lol).
I provided screenshots from my order of the sms card and also my personal informations like my name, because the game master said that they can reset it so I can play overwatch.
Well, after this a different moderator told me that they cant do anything about it and that I should get a new number or ask family/ or random friends LOL?

So what is this, there must be a way to reset my number because here in germany providers always give you already used numbers from someone that stopped using the sms card.

This system makes no sense to me and its completely unfair for new people like me…