Are you sure they are filing misdemeanor charges? PC 484e is a felony (unless all you did was hold onto an access card):
484e. (a) Every person who, with intent to defraud, sells,
transfers, or conveys, an access card, without the cardholder's or
issuer's consent, is guilty of grand theft.
(b) Every person, other than the issuer, who within any
consecutive 12-month period, acquires access cards issued in the
names of four or more persons which he or she has reason to know were
taken or retained under circumstances which constitute a violation
of subdivision (a), (c), or (d) is guilty of grand theft.
(c) Every person who, with the intent to defraud, acquires or
retains possession of an access card without the cardholder's or
issuer's consent, with intent to use, sell, or transfer it to a
person other than the cardholder or issuer is guilty of petty theft.
(d) Every person who acquires or retains possession of access card
account information with respect to an access card validly issued to
another person, without the cardholder's or issuer's consent, with
the intent to use it fraudulently, is guilty of grand theft.
The SOL for a felony is generally 3 years.
Was the offense charged first as a felony, and then dropped to a misdemeanor subsequently?