Prius forgets Phone Bluetooth configuration after turning it off

Hello guys! I've been reading these forums for a while trying to decide on a Prius and now I can finally say I'm a proud owner of a 2008 Prius with 108k miles.
I have had and still have many questions about the car, like all the weird sounds it makes compared between a normal car, I've found many answers in this forums about all those things, but there is one thing I cant still figure out...
The car has recorded all the Bluetooth phones from previews owners so I cant add my own, when I go ahead and delete all of them and add my phone, it works I can make calls and receive , but as soon as I turn off my car and back on, all the previews Bluetooth connections from the previews owner are back there and mine is gone, is this a bug? something that can be fixed?
thanks!