decline further advance

I have been an Sa Homeloans client for almost 20 years.My bond is currently at R180000.On 14/12/2015 I app**** for R30000 further advance.My credit score was perfect and all my accounts was paid up to date.My wife however was retrenched 2 years ago and there was an account that she was paying off that causes the loan to be declined.In April 2015 we deposited R250000 onto our bond account but now they cant grant me an R30000 loan.This is very unfair towards me and I feel like moving my bond.