1999 Oldsmobile Bravada back tire smoking

hi i just had my car worked on (the barring ,axel seal, and brakes) but my brakes i changed two days after having the rest fixed. The day i changed my brakes i noticed a leak in my axel seal and oil/grease on my back pass. wheel and took it back to get fixed again but my brakes started to smoke alot and they told me it was burning grease but it has been smoking for at least 4 days!!!! i would really like to know if you can help me