Horrible customer service

Horrible billing department. I moved houses in October last year and communicated this to Supersonic. They however double billed me for old and new house. Ive been struggling to get a credit note processed for the old line till today. My account is in arrears due the double billing and they offer their apologies but they still deactivated my account today. Ive been paying my bill monthly on time and the error is from their side which they keep promising to fix to no avail and they have the nerve to disconnect my internet. This is no way to treat a loyal client.