The report didn't compare your masters to master's, but bachelor's. Since you have two bachelor's degrees, according to the ECA, you should select 2 or more degrees, diplomas and certificates option.
Of course. It is 2 or more degrees option for you.
3 year PG diploma should usually be equal to a 3 year diploma [in any field]. It will fetch you an equivalent of 3 year bachelor's. Now that you have this PG diploma, you should have gone with the graduation certificate too to get two or more degrees option, for a boost in CRS score if scoring 7778 in IELTS and having 3 year foreign experience. [Just a suggestion].
For all of you who want to check the equivalency, here's the
official site.