Why am I still receiving live quotes for a subscription I've canceled?

Research and market data subscriptions are billed on a monthly cycle in advance and if you maintain a subscription for any period (even less than a full day) during the month, you will be obligated to pay as if you were subscribed for the entire month. The monthly billing cycle starts on the first U.S. business day of the month. Note that exchanges do not prorate subscription fees for mid-month elections nor do they offer refunds for subscriptions cancelled mid-month. …

Yes, if you cancel your subscription mid-month then you will receive market data until the last business day of the month. The monthly billing cycle starts on the first U.S. business day of the month.

If you subscribe and unsubscribe on the same day, you might not be charged if you never had that market data service before and did not make any trades…

As market data subscriptions move to a pre-billed model, clients may see they have been charged for a market data subscription which is typically waived due to the commissions generated in the account. 

Under the new pre-billing model, clients will be charged for all subscriptions at the beginning of the month. If the account generates the required commissions which will allow the costs to be waived, the subscription cost will be refunded during the following month's billing cycle…

If a client changes their market data status mid-month from Professional to Non-Professional the system will terminate any Professional market data and will look for the matching Non-Professional market data package. If there is an exact match, the system will automatically subscribe to the matching Non-Professional market data package and IBKR will issue a refund for the Professional market data subscription. The refund will be given typically on a one day lag from when the Non-Professional data was subscribed to. If there is no matching market data package, the Professional market data package will still be terminated but there will be no refund issued for that month…