departure airport change -my rights
I bought a ticket SDU-GRU (through OTA) some time ago for early May'2020. I did not get any notifications but , out of curiosity, I've checked my flights status on LATAM page and it shows a bit later departure hour and another airport -> from GIG airport (status shows 'confirmed') . Nobody'd asked me if I've have agreed to the change - so what are my rights now? I'd like ideally to cancel the ticket and get my money back as anyway I'm not travelling to Brasil in May and do not need this domestic flight. Well, in fact I hope that it will be cancelled anyway so that I get a full refund. I understand in any case I'd need to go though the OTA ? any advice welcome, many thanks