You have the legal right to revoke the P.O.A anytime.

For example, you may decide to handle the matters yourself or you are uncomfortable to continue with P.O.A for personal reasons.
The P.O.A is valid until revoked by you or until the P.O.A expires.
The P.O.A also becomes invalid upon the death of the person appointed by you (called ‘the Donee’)

(you will need to provide a copy of your present P.O.A.)