But after some time spending playing around with udev and usb_modeswitch, i found a way to write a udev rule which will perform a eject operation against the dongle using usb_modeswitch which will make the dongle to switch into modem mode.
Following is the content of the rule which is copied into
/etc/udev/rules.d/40-bandrich-dongle.rules
SUBSYSTEM=="usb", ATTR{idVendor}=="1a8d", ATTR{idProduct}=="1000", RUN+="/usr/sbin/usb_modeswitch -v 1a8d -p 1000 -K"
If you facing the same issue and don't own the same type of dongle, just find the vendor and product id and change the rule criteria so that it will work for your dongle as well if its supports switching the mode by performing a eject operation.