Cello repairing question??? Helpp???

Slammed car door on my cello in a non hard case. Opened it up and the C string peg cracked off. It's only in two pieces. I can't get the piece still stuck in the instrument out. I do still have the other piece. I know i should take it back to the place i got it (it's a rental) but does anyone know what they will do? How much it will cost? How long it will take? Oh, and the other strings are perfectly fine (I even can practice on them)