Is there penalty for cancelling my UOB credit cards within 6 months of issue?

Hi everyone! I applied for UOB lady's card and UOB preferred platinum visa, however did not use them for a couple of months now as Im using other cards for monthly spend. I thought to cancel, and called UOB hotline to ask if I will incur any penalty for cancelling my cards without using them & within 6 months of issue, they mentioned they are not able to advise and will call me back. BUT they never did (happened 3 times).

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does anyone know if I can just go ahead to cancel both cards, without any penalty or incurring any fees? I didnt sign up using any new sign-up promo btw.

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Thanks for your advice if you could help!