@rahmanshah123 Hi 🙂
It is not uncommon to have the odd few pence left on your balance, (in your case 0.1p)
actually the money is added to your balance and not deducted,
somehow on the odd oaccasion 1p or so has been lost during a purchase, disabling the persons ability to buy the goodybag, so it is just a safeguard of sorts, "and best ignored"
I hope this helps 🙂