Total Visa my cc pay I got my card on the 15th and I have paid it all along on the 15th sioux falls ND North Dakota Nationwide

 i recieved my card on august 15th of last year. I have always made my payment on the 15th assuming that I was ok because a normal billing cycle is 30 days. for about the last 4 months i have been charged a $37 late fee regardless of when my payment was made. I called to ask what was going on and was finally told that my payment is due on the 7th of each month. They never once told me this. I assumed since I recieved my card on the 15th that my payments were due on the 15th. I have had my card for about a year and they even gave me a credit line increase. why would they give me a credit line increase from $300 to $450 if my payment has been late every month since I got the card? also, they demand $80 every month and also charge me a $37 late fee. Everytime I get it below my credit limit, they charge me a bunch of jacked up fees to make sure they can get extra money. that way, i'm always behind on my payment. i am also getting calls and e-mails telling me that they are attempting to collect a debt? this company is crooked and they are stealing people's money and ruining their credit. i make my payment every month and even if it's one day late they charge me $37 in late fees. I pay my payment online every month. they also charge $10 if you want your funds available the same day otherwise you wait 7-10 days and they charge late fees on that too. I'm so fed up!