Pathetic call centre

For months now the call centre lines have had high call volumes. Each time I call I get cut off while waiting for somebody to answer and when they do the lines drops as well. This morning I had to call 10 times, first 7 times I get disconnected while waiting. The last 3 times somebody answers then just dead silence. I had complained to the call centre agents numerous times but there reply is basically they don't care.