Money was taken without consent

My husband had an account with Bidvest Bank. In 2021, we closed the account, as the closest branch to us was almost 100 kms away. In last week, we needed some bank statements, which was sent to us promptly. We went through the statements, found what we were looking for, but we also picked up an amount we didn't know for what it was. I sent an e mal to the guy who sent us the statements, and he told me that it is for a company call Syntech. Thr amount that went off my husband's account was for R970, and only for 10 months, then it stopped. According to Bidvest's consultant, it was a online debit order. My husband never signed anything, nor did he gave permission to have money deducted from his account for that amount. I called Syntech company, they pull shoulders, saying they can't go back so far (2019) on their bank statements, but I know they can. I need an answer from Bidvest, as to how we can get that money back, because the consultant told me it is not possible, as the account was closed. Surely that R9700 can be transferred to my husband's new account? R9700 is not small change. I am awaiting a response from Bidvest please