Colour me frustrated, confused -and pissed off with Sprint - -I said the same thing to them!! Sounds like all call forwarding useless!! the *72 charges you even if it goes to voicemail - the other 3 forms only charge you if you answer... WORTHLESS ..I told them the only reason I was using call forwarding was because they didn't have service and I was trying to avoid having to go through the contract break thing ... they said they would help me get out of the contract if I can prove enough dropped calls/no service!!
I had Sprint 13yrs ago -now i remember why I left - -been with them just over 3 yrs now - guess the only answer is root phone and go with forced roaming . ..LOL