Double debit, refund and cancel policy please!

Double debit. I changed my debit order bank details and notified M-Sure on time and this was confirmed by the policy profile administrator and the debit went through on the new account, I however receive a text stating that they will double debit as they didn't receive funds, I queried this as the debit went through and resent the confirmation from their side that the switch was successful and didn't receive any response from there. I want my money and want to this policy cancelled, maybe the communication will be clearer on this platform.