you can go to sham shui po golden computer center. There're lots of data recovery centers. You may tell them your situation, and then they will roughly test you hard disk. Next, they will tell you the possibility to recover the data. (e.g. they may tell you they could recover about 80% of data, and they need 2 days, and the estimated price is 2000hkd)
In general, the larger the size of hard disk(say 2TB), the higher the service fee.
I recommend that you should ask many of data recovery centers, so that you can compare the possibility-to-recover rates and the prices of different recovery centers.