Am i in serious trouble?

i was at a friends house last night and he wanted to do a prank call on a friend he used my phone and basically said he was from a video store and this guy owed money he then told a guy the name of a video store to go to and then later that day i was getting calls from that store, how much trouble could i get in i really worried cos i didn't do anything he made the call on my phone :S also could i get a criminal record for this if so how would i know and P.S im in Australia P.S.S i know it was stupid for me to let him use my phone so you dont have to send me on a guilt trip i am just really scared and need people help :(