Can someone please give me advice on how long payments from abroad take to reflect in your account???

Our company sold some products to a company in Senegal and are awaiting the 50% deposit to clear. The deposit was made on the 6th and the buyer said the money has been taken out from his account on the 7th. FNB said the money has not arrived yet but should have been there after no longer than 4days. If FNB is correct than either the money has not been paid infact or there is some hold up somewhere ...Any Advice?????