I made my grandpa come and now my mom and grandma are mad. Help?

My grandpa has dementia and needs to be watched so he doesn't wonder into the street or start a fire in the kitchen. Last week I was home from school and since my mom had to work and my grandma had to have her dentures repaired, I was asked to watch my grandpa. I love my grandpa so much and didn't mind but I felt a bit weird when I caught him watching in his bedroom. I had gotten a text from my friend Autumn to meet her at the mall since UGG boots were on sale and since my grandpa was watching creepy movies I thought it'd be better to take him out and away from the . Anyways, I got to the mall and everything was fine until my grandpa had to use the bathroom. I stayed somewhat outside the door to wait for him but I guess he told a tall tale to someone in the bathroom that he was being held captive and stuff and they believed him and called the cops. My mom had to leave work early and miss out on overtime pay. Everyone seems really mad at me for making my grandpa come, so how can I make things better?