Question about Apple iPhone 11

The iPhone 11 is NOT compatible with MacMini late 2014. Attention: If you want to use it as a hotspot, do NOT BUY it!!!! At Digitec, some claim I can return this electronic junk from Apple in the sense of cancelling the contract, others claim I have to pay the 10% penalty. At Digitec, one hand doesn't know what the other is doing. The most disgusting service in Bern: I had to give my Apple ID data so that they could check whether I had deregistered the device. They did NOT believe me to be honest without proof on Safari on my iPhone 6. The customer is obviously considered a fraud and an incompetent fool. By digitec. I can well do without such a shop!