Sim Activation Gone Awry

[applejacksmack2288]

So I purchased a used Unlocked iPhone 7+ from Gazelle. I took the sim card from my 5s (purchased from Walmart & using Straight talk) and put it into the phone. It worked. I've been using it for a month now, and I realized that I needed to transfer the sim card info to the new phone. I called customer service and they told me I needed to buy the kit (they could ship it), or I could go to the store to buy one. I went to the store today, and a guy who didn't even work at Walmart, but apparently works for another company trying to sell phones inside the store helped me. He said I should make sure that my new phone was compatible. That being said...
I was using the old sim card, so it should be. Before I bought the transfer kit, I used the BYOB text from the back of the kit and texted to see if my device was compatible. After a few back and forth texts with a bot, it sent me to a web page to contact customer service. I talked to a woman, told her the situation, and she told me that I needed to buy the Sim Activation Kit. I bought it. I came home. Opening the kit, inside there are 3 sim cards, 1 for Verizon, 1 for AT&T, and 1 for Sprint. On the outside of the box it doesn't say ONE THING about either of the 3 companies. My phone is unlocked and therefor non of these 3 sim cards do me any good. AND THE KIT IS NOT RETURNABLE. $48.00+ Since then I've realized that my original phone, the 5s needs to be deactivated and my "new" phone can be 'activated' with the old sim card, even though I'm using it already. I had THREE people (2 of whom worked for you) tell me I needed to purchase this kit that I DID NOT need. Help me out here please. Thank you.

[ST - Larry]

Hi applejacksmack2288. I'm Straight Talk Larry. I sincerely apologize for the unpleasant experience that you had with our service. This is not the kind of experience we want you to have. We need to further check the status of your phone number and the new phone that you wish to use. We need to take this issue offline so we can address it further. Please check your forum inbox for a message. Click on "New Messages" beside User Control Panel to view your forum inbox. You can use our self-service menu by simply texting the word HELP to 611611. Thank you.

[Barryren]

123# is to check the credit.
You should know which option you asked to activate in order to understand something more... Can you see the activation SMS you sent?