Both my service dog and I were attacked by a pit bull

I was visiting a customers home for delivery and estimate. I had in the past informed him of my service dog and he always kept his pit bull locked in a seperste room. This time I again called with. 10 min window of my arrival and when I entered his home his girlfriend said OMG, you have to put the dog away. At which time he replied she’s ok and then before anybody knew it she had lunged to my dog and the attack began. It took 3 men to get his pit bull off of me and my dog.