Refund of international roaming fund

[dinternet]

I cancelled my mobile service recently. I used to have international roaming, and tpg held $500 deposit in order to enable that. After I cancel my mobile service, I still haven't received refund of this deposit, but tpg sent me an invoice for last month's service demanding payment?! Does anyone have experience with this and how to get the money back?

[BasilDV]

We are here to help, @dinternet 

For better understanding of the situation, please send us a private message with your account details.

BasilDV