Bankstown Muffler Fit in Bankstown

He kept my mustang for 2 months. Completed no work on it and 5 months later still hasn't refunded my $1500 he owes me to add air conditioning. He never calls me and I continue to call him and all I get is excuse after excuse. He is also responsible for putting a dodgy (it looks second hand not brand new like he said) dual exhaust on my mustang. It is absolutely illegal and he won't extend the pipes. Also responsible for a dodgy central locking/ alarm he put on my car. The alarm goes off randomly at different times everyday and at night. You need to be standing right next to it for the central locking button to work and the key looks like something from a two dollar store (I'm extremely embarrassed about it).