Refund of a double installment taking more than 2 weeks

On Tuesday the 1st of November I logged a call ticket on the rain website regarding a double payment I made and requested that one payment should be returned to me. Absolutely no payment was then received and no one from Rain contacted me. Then on Friday 5 November I phoned their offices and the call centre agent said that that he requested payment during the call and it will take 3 to 5 business days. I waited the whole of that next week and still have not received the refund. Yesterday 14 November when I called Rain again I was told that the payment was not yet requested. I find this completely unacceptable that I have to beg for a double premium which was made the same day and I need an immediate payment. I refuse to wait 3 to 5 business days. This is the worst service I ever received.