FNB dispute urgent assistance

I have an issue with a debit order that won’t reverse because it was a purchase. The company that made the debit order did not give me the services that they offered, they did not disclose all the information and the consultant **** about how they work, and now I am stranded because they took my money, R3937 to be specific. FNB referred me back to the service provider to give me back my money but they are refusing to so. Does FNB not have a way of disputing the money? I know Absa does it so I would like for assistance. What can I do? Surely FNB as the number one leading bank should be able to dispute?