GoSolr deducting payment for a system that is not functional

GoSolr installed panels on my roof which have never been operational due to admin and authorization issues. They have been deducting debit orders from my account monthly in spite of numerous emails and phone calls asking them to stop the debit orders until the system is functioning. Another debit order has just come off. No response to emails or phone calls. I have now disputed the debit orders and want my money for the past 3 months refunded. GoSolr please refund me the money that is not due to you and stop charging me for services you have not rendered.