How do I change sign-up fee text in WooCommerce Subscriptions?

So far i've tried adding the following code to my functions.php with no luck:

<?php
function my_text_strings( $translated_text, $text, $domain ) {
    switch ( $translated_text ) {
        case 'Sign-up Fee' :
            $translated_text = __( 'bin deposit', 'woocommerce-subscriptions' );
            break;
        case 'Apply Coupon':    
            $translated_text = __( 'Enter Coupon', 'woocommerce' );
            break;
    }
    return $translated_text;
}
add_filter( 'gettext', 'my_text_strings', 20, 3 );
?>
<?php
function my_signupfee_string( $pricestring ) {

    $newprice = str_replace( 'sign-up fee', 'bin deposit', $pricestring );
return $newprice;

}

add_filter( 'woocommerce_subscriptions_sign_up_fee', 'my_signupfee_string' );
?>

Neither of these functions are working and I am new to changing the internals of a plugin like Subscriptions.

via Chebli Mohamed