Welcome to the community!
Could you please elaborate why you think the price appears higher than advertised? While it is possible that there is an error on the website, are you aware that the advertised prices are calcuated after bill credit? That is, the actual monthly financing for the phone is not actually reduced. Rather, customers receive a promotional credit on their bill to offset the cost of the device. For example, with the iPhone 12 Mini promotion:
~taken from here, as of Nov 16th, 2021.
The monthly financing for the phone would remain $34.50 per month (plus taxes). However, customers would receive a credit of $19.50 per month to offset the cost of the device which calculates to $15 per month (plus taxes).
It's important to reiterate that the credits do not reduce the actual cost of the phone. If you terminate your contract early, you will be required to pay the remaining balance owed on the device. The balance owed would not be $15 x remaining months, but rather $34.50 x remaining months (plus taxes). The remaining credits would no longer be applicable.
Could that be why the price appears to be higher than advertised?
Hope this helps 😀