Product: Credit card

Hello. On XX/XX/XXXX, I received a promotional email from Wells Fargo about a 0 % APR for 12 months on balance transfers and 29.99 % variable after that. Since I have other balances to other creditors that I was looking to transfer, I called Wells Fargo to learn more about the promotion and to ask how my payments will be applied should I move forward with availing the promotion. On XX/XX/XXXX, I spoke with a Wells Fargo agent who confirmed that, if my payment is not equal to my statement balance, it will be applied to the highest APR first before the lower APR. I then asked, given that the balance transfer is at 0 % APR ( for the first 12 months ), does that mean that the balance transfer balance will always be last in the order of priority when they apply my payments. The agent confirmed Yes. After that call, on XX/XX/XXXX, I transferred my balance in my XXXX account to Wells Fargo in the amount of {$1200.00}. I was charged {$60.00} transfer fee for the transfer. On XX/XX/XXXX, I received my billing statement ending XX/XX/XXXX, with a statement balance of {$3900.00}, due on XX/XX/XXXX, broken down as follows : {$2600.00} for card purchases, and {$1200.00} for balance transfer and fee. 
I do not have enough to pay the entire balance so I made sure to come up with at least more than {$2600.00} with the information they gave me that when my payment is not enough to cover the full statement balance, it will be applied to the highest APR first and then to the lower APR, and the balance transfer last.

On XX/XX/XXXX, I made another balance transfer to payoff my XXXX card balance amounting to {$780.00}. I was charged {$39.00} for the transfer. 
On XX/XX/XXXX, I paid {$2700.00}, thinking that {$2600.00} will be applied to my credit card purchases, and {$150.00} to the balance transfer. I thought that because the card purchases are prioritized in payment application, I will not incur any interest because I am paying more than the card purchases balance. 
On XX/XX/XXXX, I received my statement balance ending XX/XX/XXXX and to my surprise, I saw that Wells Fargo applied {$190.00} towards my balance transfer, and {$2500.00} to my card purchases balance. As such, I was left with balance on my card purchase. I was charged {$45.00} interest for a balance of {$1700.00} in my statement that I don't know how they arrived at. 
I called Wells Fargo on XX/XX/XXXX to complain about the interest fee showing on my XX/XX/XXXX statement, and the second agent I spoke with told me that the agent who told me that the balance transfer will always be last in the hierarchy of payment application is wrong, because their system will automatically and will always allocate a portion of the payment towards the balance transfer, even though it would mean that the card purchases balance will not be fully paid first. I was told that unfortunately, they don't have a control over how their system allocates payment, and even if I call prior to paying to inform them how I want my payment applied, they have no way of adjusting that. The agent I spoke with opened a case complaint for me for another team to review further. On XX/XX/XXXX, Wells Fargo called me and said they reviewed the XX/XX/XXXX conversation I had with their agent and they said based on their review, everything on their end was in order. 
I opened an account with another bank and initiated a balance transfer for all my balance with Wells Fargo as I do not want anything to do with them anymore. However, I would like to request your assistance in looking into this as I feel like I was defrauded. It is only {$45.00} interest, but to think about it, I was okay with paying them the balance transfer fee because I thought the 0 % promotional offer was a good deal. 
Thank you for your assistance.