Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
You may perhaps have contacted not quite the immediate company that you are concerned with. But I can advise you: if it is your service provider, for the communication, or phone, or data comm. services your iPhone is using, then you need to contact your service provider's Customer Support or Customer Service number, to ask about the two months of free service you were offered, and to cancel their (phone/comm/data-comm) service for your iPhone.
If you tell me what your service provider's company name is, I will give you info on how to contact them.
I have no power over iPhone (i.e. Apple, that mighty corporation) nor StraightTalk accounts. All I can do from where I am is advise you. (I wish I could do more for the situation, but that is about it, to be honest, since I am not affiliated with Apple nor StraightTalk.)
Ahem: from JustAnswer.com, you do have rights for a refund. Just contact
about your concern with JustAnswer.com billing and you will be able to get a refund processed there, at your request, fairly promptly.