Claiming the amounts paid for a property for breaching obligations by the developer

Hello

I've booked a unit X (and paid 10%) in a tower C of a Project of 3 Towers (A, B & C) on the basis of a swap to another unit Y in Tower B when the latter is commercialized.

There was a confirmation from the sales manager in Whatsapp for this arrangement. When Tower B has been launched, the sales manager requested me an additional 2% to secure the swap to Unit Y which I've paid (communications in Whatsapp).

After that, he told me that the swap can't happen based on a newly revised policy when the new unit should cost at least 1.5 the already booked unit. I've explained my case to CRM with no follow-up until now.

I've not signed any SPA yet and I didn't get yet the receipt of the last 2% sent to the new unit Y.

What can I proceed with in case I want to secure the swap to Unit Y in Tower B?

As well I want to cancel the whole thing?

Thanks in advance for your advice.