What can you do when the developer delays the property handover date?

Good morning,

I have a question in regard to delayed property handover.

In March 2019 I deposited 5% of the property value and signed the reservation form which stated the unit price (736,000). I was promised (verbally) that the handover will be in August 2019.

A couple of months later, I received the SPA which stated the same price and the new completion date which was set in February 2020. I refused to sign until they changed to the agreed date.

2 years after this date, I paid 20% of the unit price in total and I am refusing to pay the 5% left as agreed in the reservation form.

I met with the developer more than a year ago (October 2020) and he said he will reduce the price of the unit. But when I went to sign the SPA again, the unit price was the same and the completion date was left blank to which I have refused to sign again.

I received the handover notice today (7 days later than stated), the developer doesn't respond. What can I do?

Thank you in advance.