I made a payment on the 13th of June via link to rain as I got paid earlier

I made a payment on the 13th of June via link to rain as I got paid earlier.end of June they debit again.i informed them that I'm I payment in advance. They didn't take it serious and still deducted via debit every month. Now I'm stuck with no WiFi for this month. Thought I could use the advance this month. When informed rain they said it can't work like this and I still need to pay. I'm not happy with rain and won't recommend them to anyone as they didn't even phone me back to resolve my problem.