Do repeat spell that choose target make you choose twice to the same target so you pay the deflect cost twice?

Yes, if you use Repeat to target a unit with Deflect twice, you must pay the Deflect cost twice.

According to Rule 735.1.c, Deflect is a mandatory additional cost applied "for each time they choose me." Because Repeat (Rule 746.1.d) causes the spell's instructions to be executed an additional time, and choices for that additional execution are made during the "Make Relevant Choices" step of playing the card (Rule 746.2), choosing the same unit for both the initial and the repeated execution counts as choosing that unit twice.

Therefore, you must pay the Deflect cost for each individual instance of targeting.