Am really disappointed,I thought standardbank cares about their customers

I have an issue with standardbank vehicle&assets which I discussed with them for options I can take since I can no longer be able to pay the car installment.i took an option to sell the car, dealer evaluated it and gave me an offer.I called and apply or requested for an uknowlegement letter.It took them more than 15 days to respond.They sent me the uknowlegement letter to fill it and send it back within 48 hours and I did that.i sent the form on the 11th of April until today there is no response (it's been 10 days now).The person who is supposed or responsible to assist me never responded any of my email or calls since day 1.The uknowlegement letter was sent to me by the person above his position.his or their boss or team leader always responds,it shows that he/she forward my emails to him"please assist will below a advice"she or he responded.