Which aircraft I will be taking??
 

I am taking TK from TUN to IST on November 6th and back on 10th. According to expedia where I bought the ticket it shows an A321 on the way to IST and a B737-800 on the way back. But According to TK website, it shows A330 for both flight so which one is correct? When I bough the ticket it was A330 then changed to A321 and B737-800.

I've had same flights on 7th october / return 13th october.
It was A330 until few days before flights and that was A321 for both flights.
There is sometimes A330 on this line but there are often a lot of aircrafts switch with TK.