Complaint sub-issue: Unexpected increase in interest rate

I have a credit card with Citi Bank/ XXXX XXXX XXXX. I never missed a payment and always payed XXXX over my original note. I went out the country for vacation in the month of XXXX XXXX and had a final bill of XXXX from XXXX XXXX XXXX. I doubled my monthly note to pay that balance off. I have my bill set up for automatic payment for a long time now. Last month I started receiving notifications stating I was late and not paying enough, I was very confused because I'm never late and always pay on time. After two weeks of going back and forth with Citi Bank, the bank accuses me for signing up for a promotional balance. The accusations came from multiple management team members stating I called and signed up for s promotional balance. ONE representative accuse me of signing up through email, one accused me of cwllingbfor thr promotion, as of XX/XX/XXXX a representative accused me today of clicking on a email link. I ask for two weeks to show me proof and they can't show proof. My interest rate increased effectively without my consent and I didn't sign up for s promotional balance. I need to retrieve proof from either phone records, records of a email, or my signature that I signed up for a promotional balance. The representatives have condemn me and refuse to show proof, 3 different dates were given when I sign up for an email promotional balance. When I prove to them I received no emails from Citi Bank on the dates accused, on XX/XX/XXXX the presidential department representative assume it was a email link. Please help me. My XXXX payment went to XXXX by choice and now this company sent me a bill for XXXX a month. If this company can show you any paper trail proof to your company I would appreciate this. Please help me. This company is wrong, please request my payment history. You have my permission. I have all recording, I can send them through thumb drives or emails. The inconsistency and different stories of accusations of how the promotion offer was opened is so unprofessional because thr represenative also made thr comment that anyone could of clink on the link. The payments I've been making since XX/XX/XXXX didn't amount to anything because of the ghost interest that was placed upon me. My credit is impeccable and the interest as of date is 24.99 %. I don't conduct professional business with an elite credit card company by clicking on a link. I can provided the proof of how this company refuse to show the proof they don't have. XX/XX/XXXX the balance was XXXX with a minimum payment of XXXX. On XX/XX/XXXX my initial balance was XXXX with a minimim payment of XXXX. XX/XX/XXXX XXXX XXXX was XXXX this is the target promotional balance. I noticed the balanced wasn't going down so I added an extra XXXX to bring the balance down, never late. I don't entertain paper billing because I'm double payment set up on automatic payment. When I noticed my balance wasn't going down I tried to get into my account with the same password I used for years, I got lock out. With best Reguards I need your assistance with proof I sign up for a promotional balance that I didn't touch. This credit card company have and attempting to drain my other monthly bills and responsibilities. I'm never late and this isn't right they can't show proof but demand to charge me for something I didn't need to sign up for because I'm a responsible customers who pay on time no matter how much the balance is.