Product: Checking or savings account

I have been a loyal client of Comerica Bank for over XXXX years, and in that time, I have deposited dozens of checks, with amounts reaching as high as {$40000.00}. Throughout my relationship with the bank, I have always trusted Comerica to handle my transactions with professionalism and efficiency. This trust has now been severely shaken by an experience that has left me frustrated, confused, and disappointed. 
At the beginning of this month, I deposited a check for just under {$13000.00}, a check that was pre-printed by my insurance companyan official, legitimate document made out to me, for deposit into my personal account, which is in my name only. The check was deposited into an account that has consistently had a strong balance, with no history of irregular or suspicious activity. Given the nature of the deposit, I expected the usual processing time for a check of this type, typically XXXX business days. 
However, when I received a notice indicating that the funds would be available within XXXX business days, I thought little of it. Unfortunately, that initial estimate passed, and then several more days went by. A full week and a half passed, and still no funds were available. I contacted Comerica 's customer service team for clarification. I was told that while the check had been received by the bank, the funds would be on hold until XXXX, more than XXXX months after the original deposit. 
This information was deeply troubling to me. I have been a steady customer of Comerica for years, with no history of issues or irregularities in my accounts. I have never had a check returned, and my financial history with Comerica has been without incident. In fact, I have been inundated with pre-approval offers for credit cards, loans, and other consumer products from Comerica, which led me to believe that the bank valued my business. So, why now would they decide to withhold funds from a legitimate check issued by my insurance company? 
The complete lack of explanation or transparency surrounding this decision is both frustrating and disheartening. I can not understand why Comerica would choose to hold a check that was issued by a reputable institution, made out to me personally, and deposited into an account that has only my name on it. To this day, I have not been given a satisfactory reason for the hold, and I am left with an open-ended timeline for when I will have access to my own money. 
As a customer, I feel deeply disrespected by this treatment. Comerica 's actions have created unnecessary stress and confusion, and I am left questioning whether my long-standing relationship with the bank is valued at all. This situation has cast a dark shadow over my trust in Comerica Bank, and I am now forced to wonder if this is how they treat their most loyal clients. 
I sincerely hope that Comerica will take the time to reevaluate their policies and communication practices to avoid causing further distress to their customers. Until then, I will be left waiting in uncertainty, and I can not help but feel that the bank 's actions are less about protecting its clients and more about exerting control over the very people who have supported it for years.