ITEM PAID NO FUNDS

I have 2 unknown transactions that went off my account yesterday 30 June 2021. The description on both transaction reads"ITEM PAID NO FUNDS" with the amount of R150 for both. The most frustrating part is not being able to dispute this debit order on my FNB APP and when you call them on ***, their automated recording tell me they can't do disputes at the moment. FNB I want my money back into my account.