Report and "balance" are two separate things:
Report:
If you move a campaign (or even an creative), then with it the revenue shifts in the report. Did you previously 100 EUR revenue in CampaignA of Advertiser A, did you afterwards then newly 100 EUR revenue in Campaign B of Advertiser B.
Credit balance:
Unless you have defined your advertisers as prepaid and can cause an internal account, the account will be deducted daily at the end of the day the budget was consumed the day before. Moving you a campaign / advertising materials, then the time of settlement (1 am) are moved the data from the previous day, that it would the ad server to the customer deduct the cost even though the customer A has produced the cost B. The balance of Customer A is not changed. Likewise takes no chargeback or the like but it is as I said only looked at the end of the day what was spent yesterday and that will be deducted at the time.