Failing to pay off-plan property instalments and terminating SPA

I have booked a unit under construction with a developer 3 years ago. I paid 30% during construction and 70% was due since Jan this year.

When I booked the unit, my plan was to get financing from a bank to cover 70% payment because I was working with a semi-government company.

But I lost my job and my credit score went low due to defaulting on financing payments and I could not get financing from the bank.

I have contacted the developer asking them for refund or change of payment plan but they give me instalment plan for 5 years and increased the price which I cannot go for.

I am not in a stable situation with my current job and the company gave me 3 months unpaid leave because of Coronavirus situation.

The developer completed 100% construction and they sent me a building completion certificate in Jan this year and now they are calculating 3% late payment fee every month as per SPA.

Now I do not have any source of income. Can I get refund from developer so I can cover my expenses?