Not able to use GT Coins

Hi,

I am unable to purchase any items with the GT Coins for past few months. Now about 3,000+ coins are about to expire on 31st March 2024 and still am unable to purchase any pack. I am trying to buy the Speed Up Pack III which are available for infinite amount. The only restriction is I can buy it once a day. However, I haven't been able to buy any for 2+ months now.

Regards