Harrsased by Debt Collectors

I had a home loan with Standard Bank, the house was sold and an arrangement was made with a consultant at your head office for the repayment of the outstanding amounts. I have been making regular payments for this.<br> Last year I started receiving threatening calls and sms from debt collectors about this account. Sending sms I must now pay to them. I have contacted home loans via e-mail but being ignored. I require that this be resolved immediately as I am sick and tired of explaining same story every month to a bunch of *********** debt collectors