How to deactivate/cancel a Walmart Family Mobile service?

I have a phone from Walmart that is on the Family Mobile plan and I'm planning on getting an iphone 4s. I know that the sim cards on the Walmart plans only use regular sims and the iphone 4s takes a micro, I have a cutter and am going to cut the sim card to fit. I'm also going to unlock the phone so that it isn't linked to any carrier and can be used with Walmart Family Mobile. My question though is, can I completely cancel the plan/service I have now? When I get this iphone I would like a completely clean slate, new number, sim card, everything. So is it possible to cancel the service I have and just get a whole new one with the same plan? Sort of like the plan I used to have never existed. I know this sounds kinda sketchy but I just want don't want the number I have now (because I get so many random texts/calls) and just want a fresh start.
Hope this makes at least some sense!
Sorry this is so long, just wanted to give as many details as possible!

You don't need to cut the SIM or cancel your current plan. Family Mobile can change your number for you as well as give you a micro SIM that will fit the 4s.

i want to cancel my wallmart famil plan and go full tracfone where u need to buy min how can i do that?