@Adriana so the situation is like this:
1) I’ve ordered Samsung Galaxy S7 black and Samsung Galaxy S7 Edge black
2) I’ve paid for both phones while ordering online
3) I called UPC hotline to change color of S7 from black to white (within minutes after placing my order after it was already paid)
4) I received Galaxy S7 Edge black without any additional cost
5) I received Galaxy S7 white with additional fee of 249 CHF to be paid on post (which I already paid while ordering the phone, so this is my dual payment) - before getting the phone from the post I called UPC hotline to confirm I will be paid back what I already paid.
6) I sent an email to UPC support on 22nd April to get my money back (as advised on the hotline)