And they belied Our signs fully.
And utterly rejected our signs
and they absolutely belied Our verses
And rejected Our messages, giving the lie (thereto)
And they lied/denied/falsified with Our verses/evidences lying/denying/falsifying
And treated their Lord’s revelations as a lie and false statements
And they denied Our signs to the extreme
And rejected Our Signs totally
And they used to utterly deny Our signs
And they had belied Our Messages outright
But they belied Our Ayat (proofs, evidences, verses, lessons, signs, revelations, and that which Our Prophet (Peace be upon him) brought) completely