Unknown monthly debits from bank account for more than a year

I sent an email to Nedbank last year about unknown monthly debits on my account. They're all small amount and the descriptions change but the end of the description all states "EM - "8 digit number"". The one states Rescuebox and another Hotspotter and another Kin Tel. There are about eight debits all under R100 each. This adds up to a lot of money and Nedbank just doesn't respond to me. I've emailed to ********** At one point a lady responded but then no response again. I don't always have time to check my banking transactions but was reminded about these debits again when I checked my bank statement. This is ridiculous that my bank just allows debits and don't investigate this. I expect this money to be reimbursed since the inception of these debits. There must be a ombudsman to deal with this. Someone please help.