Money taken *******ly from my account

I have been renting a storage unit for 4 years from Gregory Self Storage and paid diligently my rent in advance for 48 months. I gave notice a month ago according to the terms and vacated my storage unit on time and left it clean. This morning I found that the **********ly took money from my account for March 2019 rent and also send me an Invoice. I emailed them just to see how they open the email with no reply. If i do not have my money refunded today I will open a case of *****. Please be careful using them. Franscious Myburgh Unit 102