Sprint Nextel Corporation Trouble Getting Them To Keep Their Promises Overland Park, Kansas

In early January I bought a Sprint phone. When I returned it I was told there would be a $35 restocking fee.  I called Customer Service and a supervisor agreed to remove the fee for a phone that did not do some of what was promised and had at least one operational defect. Because of his help we renewed the contracts on all four phones. The charge appeared next month, but not the credit. I again called Customer Service and learned the original promise was never documented but, after a 54 minute call, I was given a 50% credit.  

I asked how I could protect myself in the future and was told that even if I recorded my conversations, sometimes I might be told things that Sprint could or would not honor. In other words, Sprint was reserving the right to mislead me whenever it fit their purposes. In a follow-up conversation, I was told that that was not true (how surprising!), but my concern is that it truly appears to be the way Sprint acts, or at least tries to get away with.  

Has anyone else had similar problems?