WRONG PRODUCT

I went to Telkom express in Canal Walk, Cape Town on the 18/02/2024 to enquire about the laptop that my son needed for his varsity, they suggested D16 I9. I confirmed with my son before I ordered it. They called me to collect it because they didn't have it in store when they got it. I collected it, before they gave it to me they opened it to confirm & I trusted them since I have many accounts with them. To my surprise when I got home same day my son told me it's not the I9 but an I5. Since I was going out of town soon as I came back I took it back to them since I had informed them in less than 12hrs that they gave me a wrong laptop. I came back from GP & I gave it to the manager of the day. Now it is more than 3 weeks later they are forcing me to come back and take the same wrong laptop which my son can not use for his varsity project. They have it with them as they opened it & they are forcing me to take a wrong contract. Since my son was being left behind I was forced to take another telkom contract on the same canal walk for the right D16 I9 at a different shop. I do not need the i5 & they are forcing it to me because they can't take responsibility for what they did. The product is with them in the same condition they gave it to me. Kindly assist