如果有買家居保, call agent is the most efficient way. The insurance company will pay you first and claim the owner of upper floor apartment. But you have to pay more when renew the insurance.
If the management office is helpful, call them to check the status every one or two days. But if the owner of upper floor apartment deny or refuse to do anything, you may have to raise it to court.
"d人就係咁,好聲好氣唔得,係要被人告至安樂" ... Unfortunately, it is ture. So you have to inform the management office and the owner that you will sue the owner if he/she does not fix it as soon as possible. Usually, one week is reasonable enough.
According to my experience, the owner usually has to pay a lot more when the case goes to court.
Without 家居保 isn't a big deal. You can do it yourself.
I met the same case twice. For the first time, we settled in court within 5 months. For the second time, with the experience learned from first, we settled in managment office in 2 weeks. I showed the owner the court form (a simple form downloaded from 小額錢債審裁署) and a brief list of claimed items. So the owner knew I was serious and promised to fixed it in 2 days and paid half of the claimed items.