Do you think I was wrong in this situation?

Hi. For months and months of planning to go to the gym, I finally did it. I enrolled and took a personal trainer at this home gym near my house. I just started this week actually, but something happened last night while I was there.

Before I started this Monday, I paid the personal trainer a paper of P1,000 and another paper of P500. The payment for a month with personal trainer is P1650. I don’t have any money left, so she told me to pay the P150 when I go back. She’s the only person who handles the gym.

Before we started, she took my measurements and she let me sign attendance and that’s it. It’s not a personal training because I’m with a group of girls who are also her clients. I was expecting she’s going to handle us one by one but she put us in a group. I wasn’t able to go on Tuesday because my body was sore and I needed rest.

Yesterday I went back, and she gave me back my paper of P1000, and this time my money was torn. She told me I gave her a torn money and she would not accept it. This is what it looked like. At first I was confused, because I’m pretty sure I paid her my money not looking like that. The paper I gave her was directly withdrawn from ATM and it is not torn and have any marks, as you can see there’s a red mark on the upper left.

I asked her nicely if she’s sure that it’s my money, and she told me that I’m the only person who paid her for PT this week, so the money she only has is the money I gave her. To make it short, this was our conversation.

Me: Are you sure this is my money? Because I’m pretty sure the money I gave doesn’t look like this. I’ve been keeping that money safely in my wallet, away from any zippers that might tear it. And it was new and directly withdrawn, it doesn’t have any damage.
Her: You gave your money folded so I didn’t see it clearly.
Me: So why didn’t you contact me and told me it’s torn? How would I know now that you didn’t change my money?
Her: I don’t have your contact number and you didn’t go here yesterday.
Me: So why didn’t you get my contact number? You just took my measurements and made me sign attendance but you didn’t take my other information?
Her: Are you sure you didn’t sign in my logbook? Every client signs in my logbook.
Me: Yeah, I’m pretty sure. You can even check it right now and show me where’s my info in your logbook. (She won’t check it)
Her: You know, if you don’t want to pay me, it’s okay with me. I mean, it’s just money and it goes back.
Me: Yeah, but it’s my money I gave you and you’re giving it back to me torn. This isn’t what I gave you. Why didn’t you check it and gave it back to me as soon as I gave it to you?
Her: You gave it to me folded! And I have other clients, I’m busy when you paid me and I didn’t see it!

I got so angry I shouted at her in front of her clients. I told her “Next time, if someone’s gonna pay you, check it right after they gave it to you!” and she told me not to shout at her face. What made me so mad was when she told me it’s just money. Yes, it’s just money, but it’s my money! I care for my money. I gave it to you with no damage and you’re gonna give it back to me like that? I told her I’m not going to accept it, and I demanded a refund. She told me to leave and I thanked her for giving my money back before I left.

I was wondering now if I was wrong in this situation. Maybe I was wrong for shouting at her. But other than that, do you think I’m in the wrong here? I felt like she’s trying to fool me right on my face.