Belong Mobile Outstanding Balance

Hey guys,

I've got a Belong account which has $10 outstanding balance due to abandoning a temporary number that I got for my parent. Recently, I have been trying to active a $40 SIM under this account with a referral code but it keeps complaining my payment method (debit card with $2 balance) not being valid. My theory is that despite having $60 credit in total once activated ($40 prepaid + $20 referral) it'd still want to deduct $10 outstanding balance from my debit card BEFORE activation.

Does this sound familiar to you? Is there a way around it without registering a new account?

Thanks in advance