No.
Guangdong Development Bank is a small bank. It is impossible to have a branch in Guigang. Guangdong Development Bank's outlets are concentrated in the Pearl River Delta.
If you want to handle repayment, you can use Lakala. However, it seems that there is no Lakala in Guigang.
You can also make repayment via online banking transfer or use Tencent Tenpay to repay.