The audio sounds like "Je vous le transferais" - I couldn't/didn't hear the additional "er".
Definitely an issue with the female voice in the audio - she clearly says 'transferai' and not 'transfererai'.
I don't know what you heard and I agree with problems in the female voice, but the French "run over" syllables in future tense of "faire." They pronounce, "frai" for ferai, "fra" for feras, etc. I learned this on a French Today tape. Some may call it street French, but it is real.
Je le transférerai pour vous/toi. But when shown as an indirect object pronoun (je vous le transférerai), means "I will transfer/forward it to you (not "for you").
Could someone explain the difference between this given example using "transférerai" and the other given sentence before : "Je vous le transfèrai. "
Are "transférerai" and "transférai" interchangeable?
I suspect that something is wrong w/the translation of «transférai». It is passé sample of «transférer», but the page translates it as "I will forward it to you".
Did you report? One option is to ask this question in the main French forum; sometimes, the contributors see things more quickly there.