If you have an outstanding bill for services for any reason, you need to apply a deduction from your balance. This usually happens when a bill is issued, but there are no funds available in your balance. You can pay the bill by going to it and clicking the "Pay now" button.
Alternatively, you can add funds to your account balance and then deduct the funds from it. Once there is money in your account balance, you need to go to the billing section.
Open the outstanding invoice.
Then apply the funds from your balance by clicking the "Apply credit" button.
Your invoice is now paid, and if your service was suspended, it will soon be reactivated.