you can take MTR Island line from Chai Wan to Quarry Bay and change Tseung Kwun O line from Quarry Bay to Yau Tong.Finally,change Kwun Tong line from Yau Tong to Kowloon Tong Station and get off at exit E or F to take minibus No.29A
Fee:$11.2+$3.9=$15.1/$5.4+3.9=$9.3(for Octopus)
$11.5+$3.9=$15.4/$5.5+$3.9=$9.4(for single ride tickets)
Kowloon Tong station street map:
http://www.mtr.com.hk/jplanner/images/maps/kot.pdf
Hope above information can help you!