Temp loan

I just received my May monthly credit report and discovered that my score went down by 20 points because of the apparently Temp loan of R2409 that I took in April 2023 and fail to pay it off. But in April I did not have an FNB account as I closed FNB in FEBRUARY 2023.

So how possible that I can get temp loan but I don't have account with them. Can FNB correct this and clear my name on all credit bureau companies please.