FNB business poor service

I paid funds into a fnb business account from standard bank business. after 5 working days the money still doesn't reflect, i confirmed with the account holder to double check their account details and it corresponds, i requested for a reversal which my bank did but the feedback from FNB is pathetic, now the tell us that it is for a personal account. how is it possible to have duplicate account numbers, when i phone FNB business division i wait for ever to get thru and then the lady on the other side drops the phone.