So where did the purse you exchanged come from? If you purchased it and do not have the original receipt but paid for it with a debit or credit card, there will be a transaction number associated with that payment on your bank/cc statement. Your bank can help you with this.
Belks (and/or their bank) can reference the original sales receipt/transaction with that info. If they are uncooperative the info might have to be subpoenaed. All this info is on computer databases and isn't that hard to access if someone actually wants to.
Now, just because you may have purchased one of these purses before doesn't mean the one you exchanged was that one. It could be you actually did shoplift the returned purse as the LP officer said. But having a record of purchasing might well raise some reasonable doubt.
Given the short time until your court appearance you should get that aloof attorney of yours to answer whether or not he will be representing you.

