Poor service from Discovery Bank

It's taking discovery close to a month to cancel a 90 day savings account. I have called their call center 3 times and they keep escalating but nothing gets done. I hold so much with them that each time I am on a call with them my airtime cuts. They do not return calls not do they bother to complete the case after the person is out of airtime. I joined discovery recently but the service so far is not great at all.