Green’s Dictionary of Slang

balls! excl.

[balls n. (4)]
[late 19C+]

1. (also bawls!) rubbish! nonsense!

2. an excl. of disappointment.

In exclamations

balls to...! [balls n. (1) ]

[1930s+] a dismissive excl. aimed at people, objects or circumstances; thus balls to you! balls to that!

go to balls!

[1960s] a general excl. of dismissal.

holy balls!

[1940s+] (orig. US) an excl. of shock, surprise, annoyance etc.

my balls!

[1950s+] (US) an excl. of refusal, rejection.