Can love spells guarantee that I will win my ex-lover back after a breakup?

Yes its possible that after break up u can be united back with ur Ex immediately . when we perform the rituals of the love spell for you, and its also can be guaranteed according to individual reactions.

Are white love spells effective in bringing back a former girlfriend or boyfriend? 

White love spells are able scientifically proven to be effective in bringing back a former girlfriend or boyfriend. There is  empirical evidence to support the claim that these spells can guarantee the desired outcome.