No response to my Smart bond query

I have a smart bond account with FNB. I have left messages via their call centre and sent two emails of which the first was on 24 July. Until now I have received no reply. I have a simple query regarding the settlement of my bond. To talk to them on the phone seems almost impossible as the lines are always busy. Emails are responded to with an automated email and nothing after that. I have been a customer with FNB for more than 20 years but am very dissapointed in their lack of response.