Short answer: no alternatives for Broadband on Lamma, it's a very slow-speed monopoly for PCCW.
You can get the same service on the same PCCW lines a bit cheaper service from Netfront on a shorter commitment, but the actual service and support would be provided by the same Netvigator staff.
Only alternative is giving up your Broadband line and going 3G/4G wireless, but it's much more expensive and has a monthly data cap of 5-10GB, so forget streaming TV or downloading movies. It can be several times faster than PCCW Broadband, but it completely depends on location, from no service to great service. Broadband works slow, but reliable almost everywhere on Lamma.
Check your mobile phone data speed inside your flat. Set the phone as a temporary Wifi hotspot at first and if it works well, consider a Wifi router with a mobile SIM card.
More info and detailed discussion on Facebook:
Faster Broadband for Lamma.