We can’t assure you of any score on the IELTS, because we can’t be sure how much time you are going to study our materials. If you buy our materials and never look at them, you are not going to improve your score or abilities. If you buy our materials and study with them every day for a month, you will surely improve your score, skills, and abilities.
It is totally up to you how well you do. Our course and materials are a great companion to help you achieve the success you want, but ultimately you are the one who needs to spend the time studying them.