Shipping amount error

[safiulrehman]

I have created 4 rules in back-end of your extension as written below:

1. If subtotal is less than 300 then Cash on delivery price = 20
2. If subtotal is greater than 300 then Cash on delivery price = 10
3. If subtotal is less than 300 then Credit Card price = 15
4. If subtotal is greater than 300 then Credit Card price = 0

For subtotal less than 300:
There are two option available on check page. One for cash on delivery with fee 20 and other one is for credit card with fee 15. I can choose credit card option with fees 15 and place order with cash on delivery.
Same scenario is for subtotal greater than 300. There is no restriction for user.

Expectation of work:
When user choose credit card fee it should only place order with credit card and if selected cash on delivery then it should allow order with cash on delivery.

Screen shots:
http://i.prntscr.com/lmKooB9qTGui-MUWKC9bmA.png
http://i.prntscr.com/QTn34ZWLQF6ngnbEFwB__g.png