> stash your money under your mattress like grandma taught you

This is, unfortunately, the wrong conclusion to draw from this experience.

First, the charge was not waived. You were provided a provisional credit or temporary removal of the charges while an "investigation" can be performed.

Sometimes these "investigations" are cursory at best (at least initially) and it seems that many of the bigger banks do tend to rule against the customer (again, at least initially).

Often a reason is provided. Often you are allowed to contest the decision.

It is at this point that you may be asked to submit further documentation. This may include an affidavit attesting that the charges were fraudulent. This may include a copy of a police report.

If all that fails to result in a satisfactory conclusion, then moving to government regulatory agencies may be considered. This would include the CFPB.

As to stashing money, "under your mattress" will lead to financial inefficiency.

Instead, you should be following the Prime Directive.

• https://www.reddit.com/r/personalfinance/wiki/commontopics