Product: Checking or savings account

Ive been with American Express XXXX XXXX for over XXXX years. Ive deposited numerous valid checks with them in over XXXX dollars. Just recently, I submitted some checks that I received from the XXXX XXXX XXXX  XXXX, government checks. During the process of submitting the checks, the money begin to be available, I was able to make XXXX transfer because some of the checks were cleared. During making a XXXX transfer, I noticed my account was locked. I called and they stated some checks were returned. They made me go through paying and getting affidavit, which is a sworn testimony from a licensed notary who I showed my XXXX state id, and had me send it in in order to get the remainder balance in. These checks were submitted way back in early-mid XXXX. Keep in mind they would have returned by now. So I spoke to XXXXXXXX XXXX XXXXXXXX, they stated that they can see some checks were returned because someone closed my claim out during the process of them sending me the checks and cashing them. Therefore, when they closed the claim it voided some checks. There were a total of XXXX checks that returned XXXX {$660.00} and another for {$260.00} ... .All the others that were submitted on the XXXX of XXXX I believe or even could have been from the XXXX batch I submitted on the XXXX. Either way they were returned. So this was an error on department of labor. American Express has not been helpful and has given me the runaround to get the remainder of the money of the checks that were deposited. Back to the affidavit, I turn it in immediately with my current id and address sworn in. I Call back because that's what they requested. Call back and they tell me they have a different address, which I didn't know I didn't update it. Keep in mind the checks that were cashed have my current address on file but they had no problems cashing the checks. Now they tell me they can't accept the XXXX. People forget to update addresses all the time. Ive submitted a sworn In, they even verified the XXXX and still didn't submit my check. Now they tell me they have to call the bank to verify the checks. This is down right unfair and its totally not acceptable and is not the way you treat a consumer who has been with them for a while. Its unfair. Im completely appalled that I'm being treated this way. I have had so many checks deposited and cashing history with them. 
I admit there was a small check that may have returned last year for maybe {$300.00}. That's it. That is still not the way to treat consumers who has a great history and deposited a large number of checks, no issues. Its like there trying to take me around the world and playing games to not send me what's in my savings and its downright wrong, They have numerous complaints for the same thing when I researched online. Im really thiking about seeking possible attorney because they will not give me my money. 

XXXX XXXX XXXX XXXXXXXX has reopened the claim and resubmitted the checks that were returned to me so that I can cash them. I have attached that documentation to show proof thus was an error on XXXX part, I even tried to submit the paperwork to American Express Savings and they didn't want.