INCORRECT AMOUNT DEBITTED

I joined Ample Insurance Brokers in March and received all my documents. Stipulated in the contract that on 25th of every month my debit order will run for R749.05. So i made provision for this amount monthly then coming to June 25 an amount of R841.56 was taken from my account. I then contacted their offices on 26June and spoke to 2 different ladies who promised they would call me back with my query! No response made me call them back and i spoke to Merezel who then advised me its the first time this happened but their system made an error and took more than just the premium amount- not just from me but we were a couple of clients that were affected. She then advised that her manager would get in contact with us- however i feel they were very quick to debit these amounts from my account now its an effort for someone to fix it. i have still not received no call, nor feedback neither was the extra monies refunded into my account. This is scary since i am fearing for the day that i have to submit a claim what will then happen?