Bogus billing. They ***** your money!

Rain has been billing me twice. My current debit order (as agreed) is set for the 15th of each month. However around the 1st of the following month (less than a month later) they disconnect my internet and prompt me to pay again. I have called their customer care line. After waiting almost an hour to get my calls answered I did not get assistance. Instead their team insists that my billing date is the 1st day and the deductions made twice are fine. I have emailed their complaints department with no assistance or responses.