Calculation not properly calculated

Hi there,

My problem is similar to someone earlier on. I had a problem with Canada and the USA categories. I’ve set the weight and shipping rate:
0.5|21.10|1
1|36.70|1
1.5|49.55|1
2|63.90|1

for Canada and the USA
the shipping rate should be charged only 21.10 but the calculation on the checkout page was $63.90.

Another problem is I added one more item onto the cart and changed the shipping address to Australia just to check that there would have a problem with other countries or not.

So, I changed to Australia and the correct shipping cost should be $9.5 as per the below table for Australia which is under the country group 2. But the calculation on the check out page was $27.39 which is not in the table set at all.
0.5|9.5|2
1|14.5|2
1.5|19.9|2
2|24.9|2
Here screenshots from when the issues were occured.
https://www.dropbox.com/s/265d1ozz2k0tztl/Screenshot%20from%202016-02-13%2011%3A32%3A17.png?dl=0
https://www.dropbox.com/s/ij4wa0llbvpe6jt/Screenshot%20from%202016-02-13%2011%3A33%3A48.png?dl=0
https://www.dropbox.com/s/gdsrt85bnewncwh/Screenshot%20from%202016-02-13%2011%3A37%3A01.png?dl=0
Thank you very much.
Regards,

https://wordpress.org/plugins/oik-weightcountry-shipping/