Drunken sil tells me im a liar how would you respond?

my brother is at the beach and every year they ask me to take care of their dog. first night their there sister in law calls me up while im in her kitchen feeding the dog treats and asks if I did the dog. I tell here im there I just did 2 laps around the house dog pissed twice and took his shit for the night. call ends she seems ok. I get back to my house 15 minutes later she calls me again and asks how's the dog like we never even talked. I said we just went through this. dog was a fine I did 2 laps with him. she calls me a liar because she didn't see me on her cameras. I said if you don't trust me im not stepping foot in your house again and to find somebody else to take care of the fucking dog. im doing her the favor I was there did the dog. she's just wasted and apparently can't operate her phone this drunk. I also said now ya pissed me the fuck off and im not going back to take care of it again and hung up on this bitch.. how you gonna react when your told that your a liar when you just got done doing what your accused of lying about? I don't take someone calling me a liar lightly to begin with but right after I just got done doing them the favor and then being accused of lying set me off. she is wasted I can tell and she just thinks whatever she believes when she gets to this point.. so what did I do wrong here? please share what your reaction would be.

Drunken sil tells me im a liar how would you respond?
Post Opinion