Do you have any experience with Smartphonemittarif.de?
I'm interested in potentially booking an all-network flat rate there, but I'm not familiar with the provider yet. Unfortunately, I haven't received a response to a WhatsApp message I sent in five days.
Basically, the shop is fine. This is a small company with a webshop and a manageable team. That’s why an answer can take longer.
But the operator is known in the industry and doesn’t make any crap.