Retired, it is fairly standard practice for credit card issuers to adjust credit limits up or down depending on either an individual's financial situation or as a result of the current economic climate (i.e. 2008).
There is no requirement of advance notifications of credit limit changes, it would actually be counter productive, so you will not find many issuers that will. You can set your document preferences in your USAA account to receive these online rather than via snail mail.
If your credit is good, then just apply for another credit card somewhere (barcleycard has a pretty good interest rate if you qualify) and that will solve your issue. More than like it isn't and that is why your limit is being reduced.
It is extremely difficult understanding the meaning of what you are writing when done in a run-on sentence.
I am so sorry to hear you have been unhappy. I appreciate you taking the time to post here and share your expereience. I have sent your concerns to our banking edepartment for further review. Thank you.