Sms saying I'm in arreas

I am really unhappy with the service of on airtv, I keep getting SMS that says I'm in arrears while payment is paid monthly without fail via debit order... I have tried emailing them no response, they do not pick up their telephone lines just keeps ringing, I have tried their whatsapp lines no response ......very unprofessional terrible service, i can't wait for my contract to expire, so I can get rid of them... And this is not the first time I have experienced this type of pathetic service previous to this when I was double debited due to a technical error in their side I emailed them to query and request a refund and they rep**** one month later.. ????