Straight Talk, Inc Would not refund a SIM card that did not work Miami Florida

Purchased a SIM card kit from Walmart for Straight Talk on 7/16/18, had my own phone which I tried to activate using their cell service. Called several times and tried to have the service activated through straight talk customer service. They asked for me to scratch the "service pin card" to activate the service. The phone worked briefly but stopped shortly after my conversation with customer service. I called again several more times and was told that My Phone was NOT compatiable with their cell phone service and that I needed to go back to Walmart and receive a refund. Went to Walmart and they checked the "service pin number" and said it was activated and I could NO longer receive a refund from Walmart. They told me to go back to Straght Talk. I called several times, was transferred to five (5) different customer service agents and so-called managers (while they were laughing in the background) was hung up on two different times. No refund and stuck with their SIM card that I can not use!