I got these tennis rules :

1. Moneyline Wagers
In a head to head matchup, one full set must be completed for Money Line wagers to stand. If less than one set is completed, all Money Line wagers will be cancelled and funds returned.

4. Delays and Shortened Matches
If a tennis match is completed, all wagers stand. A delay in the start of a match will not affect any wagers, nor will a suspension, as long as play is resumed and the match completed. In the event that a match does not go the expected number of sets, and the match is shortened by officials, the bets will still stand as long as an official winner is declared.

In your case, three sets already completed and Feliciano Lopez retired at fourth set. And the official winner from this match has been declared, Adrian Mannarino. Therefore, both conditions has been met and you lost your bet.