Apology for creating false impressions

Dear {Recipient},

Please accept my sincere apologies for creating a false impression about {product/service} when we spoke {on the phone/via email} {last week/the other day/etc.}. I understand how the lack of information about {the price/features/etc.} could be misleading, which I assure you was not my intention.

To help you understand our {product/service} better, kindly refer to the {factsheet/link/etc.} I've attached.
Please don't hesitate to reach out to me should you have any further questions.

Warm regards,

{Your Name}