That statement is categorically false and slanderous.
The Mass is not a "re-sacrifice," nor is it a "new sacrifice," nor does it sacrifice Christ "over and over again". It is a participation in the one single sacrifice of Calvary and makes that sacrifice, which is eternal because it is present in the heavenly Holy of Holies (read Hebrews) present to us in our time.
When the priest pronounces the tremendous words of consecration, he reaches up into the heavens, brings Christ down from His throne, and places Him upon our altar to be offered up again as the Victim for the sins of man.
John O'Brien, The Faith of Millions, p256
The book is stamped Nihil obstat: Rev Lawrence Gollner, Censor Librorum; Imprimatur: Leo A Pursley, Bishop of Ft Wayne-South Bend, March 16, 1974
360. Why is the Mass the same sacrifice as the sacrifice of the cross?
The Mass is the same sacrifice as the sacrifice of the cross because in the Mass the victim is the same, and the principal priest is the same, Jesus Christ.
Baltimore Catechism
The devil is in the (theological) details.