Mom getting scammed

My mom has been dealing with dementia for a couple of years. It has progressively gotten worse. Supposedly the more times they have gone under anesthesia it can speed up dementia. She went under 3 times last year. But even before that she had issues with scammers. She lives in an AL. I have had my hands full from time to time getting new cards, checks etc. She of course never remembers that she did any of it and I understand that, so I have locked down her bank account. I got creative; since she wanted a debit card, I opened up a separate card and deposit money in there in case she wants to go shopping or eating out and has a bit of "independence" from me. So that is a win for both of us. But she calls me occasionally asking about her check book and if I have it. I don't, it is locked up in her locked cabinet, but she doesn't remember that. She called on Friday and asked and I said why do you need it? She said she was on the other line with someone and never mind and hung up on me. I called right back on her cell phone and she answered but didn't put it to her ear and I could hear her talking to someone on her landline. He was telling her to look here and there for her checkbook. I was screaming at the top of my lungs but of course she couldn't hear me. I hung up and called back and she was upset with me calling her back. I told her I was heading up there and not to do anything and she said she could figure this out and hung up on me again. Once I got there she didn't remember much of it, other than when she told him I was on my way there he hung up on her. I said why did you need your checkbook? She said he wanted the address for my bank. I said mom he wanted your bank account number. I told her I really want to get rid of her landline. Not kidding she gets at least 15-20 scam calls a day! My rule is don't answer the phone unless you know who it is. If it's important they will leave a message for you to call back. She can't remember that and at time I think she does it to spite me. She doesn't want to get rid of her phone because she's had it forever. I get it. But there is no stopping these calls. She gets scam text on her cellphone and that is just about as bad. I want her to keep her dignity by not treating her like a child, but it is so hard when they have some independence and can be dangerous. I have everything locked down I believe but I still have to clean up so many messes and she can't understand that part of it. It breaks my heart. I'm not writing this for answers I'm just venting because I don't know a lot of people that would understand or are going through this. Thanks in advance for understanding!!