The last time a customer at call center got angry with me was way back in February this year. What happened was,they're having an issue on their homephone service and since they're on a copper line their internet is also affected. There were lots of escalations made to our technical support but got no luck at all because it's a congestion on their area.We offered customer to disconnect their services and we'll waive off the cancellations fees but customer declined and insisted that we have to fix the issue.I even advised the customer that I will close the complaint as dissatisfied but customer declined as well.Until one day, I got tired of communicating with the customer because it took a year that the case was on my bucket .I did not call the customer anymore and after few weeks they requested a callback from me. I did the callback and customer was furious at me and then they escalated their issue to the external body. When I revisited their account ,their issue is not yet fix until now.