Most Appalling Service Ever!!!!!

According my contract, I gave SADV notice MORE THAN A MONTH AGO that I am cancelling my account with them at the end of July. Incredibly, they sent me an invoice for July, and, despite having logged numerous tickets, I don't get an replies. I phoned their helpline and spent more than one and a half hour in total waiting for somebody to assist. At one stage I was no 1 in the queue, and stayed number one for more than twenty minutes before I finally hung up. I sincerely doubt that they have people answering any telephone calls. They have not terminated my line, which means that my new service provider is unable to connect me. I have never in my life experienced service like this--absolutely appalling!!! Just look at the number of bad reviews on HelloPeter and then decide if you ever would want to do business with them.