I have been a Boost Mobile member for over one month. I purchased a new Samsung J7 Perx, and only after a month and just seven apps, the phone has slowed down substantially. I want to switch back to an iPhone 6 that was deactivated from Verizon. Can I use my current SIM card from the Samsung phone and put it into my iPhone 6 to "swap devices"? Or do I need to purchase a new SIM card?