A TA should never be charging a credit card to an agency. This is how it works, TA calls the Cruiseline, Holds a Res, gets a fax, She may give the customer that price or discount some of here commission which most TA's do unless its a real cheap cruise, then when the client gives the TA the charge # and permission to use it, the TA calls the Cruiseline and the Cruise Line charges it to the customers Card. Same with final payment. The TA's commission is mailed from the Cruise line. It can be minus the discount she gave the customer.
Make sure when you get a quote port and Govt taxes are included. Some TA's exclude this and then you are really paying more than quoted. IMO , An Honest TA will include everything.