DOUBLE-BILLED - PAYING FOR 2 CONTRACTS IN ERROR

In September I signed up for the new optic fibre contract at R699. I was paying around R500 a month for my ADSL contract including a phone line. From October I've been paying for 2 contracts, the old plus the new. I'm trying to call 10210 to sort this out but the line just dies after a few minutes. I want a refund for all those months that I\ve been overpaying. From October 2015 until February 2016."