The same here with two local banks here in Malaysia called BCB and Public Bank.
I have accounts in both of them and while activating the internet banking stuff I asked both the banks whether the portal is non-IE compatible. Man the looks I got just for popping up this question
One person at BCB even told me "Sir there are no other browsers available other than IE."
Then I took upon myself to enlighten the poor individual on the options available on the other side but at the end to no avail. What he said was if the OS is free it is not good.
The Public Bank fellows gave me the stock response that the user base is too small to make the portal non-IE compatible but at least they knew that there are other browsers available