Best Calling Card

I have 4 phones on my account.  One was ready for an upgrade credit of 150 but we didn’t need a new phone for it.  On the other hand, another phone was lost so we used it and got a phone for the other line.  It was supposed to be free with 30.00 (if I recall correctly) rebate.  I sent in the rebate, it was processed and got right to the point where a check would be mailed and then they denied it.  Said that the phone was not active on that account so it was not eligible.  As far as I am concerned, they are all the same account.  Maybe a different phone number but technically it says the phone is to be active for 30 days on the ACCOUNT.  Why was this denied?  I still put myself in another 2 yr contract on the one phone either way.  Why is this?  I think this is somewhat deceiving.  I would have returned the phone and cancelled the phone number I reupped but they conveniently didn’t send me notification with in the 30 days when I could still return the phone.  Made me very angry at Sprint.