Formula to Sum based on 2 criteria

Good afternoon,
I have a spreadsheet in which i have to pull out the amount of calls by customer by time frame.
Column A is "Time Frames" IE 9am, 930am, etc
Column B is "Customer" IE Customer 1, Customer 2
Column C is "Calls" this is the number of calls that are made in a specific interval by a specific customer

Now what i need to do is come up with a formula that i would be able to show that at the 930am interval Customer 1 made 4 calls and Customer 2 made 3 calls.

Below is a sample of the worksheet i have. can anyone help with this. i have tried. Countifs, Match and Sum but cannot figure out the right Combination to get the numbers i need


Time Call Work Code ACD Calls
8:30 AM Customer 1
8:30 AM Dealer 1
8:30 AM Customer 1
8:30 AM Dealer 3
9:00 AM Dealer 3
9:00 AM Dealer 1
9:00 AM Dealer 1
9:00 AM Customer 1
9:30 AM Customer 1
9:30 AM Dealer 2
9:30 AM Dealer 1