Further update: Since my above posting the TA at SeaMiles has called me back twice. The first time he told me the final figure he gave me (and the one on which we booked) was not right it was $300 more. I got out my notes and we went through all the costs and deductions step by step. He seemed confused but finally agreed, 'yeh, I guess you're right' .
Thirty minutes later he calls me back very indignent and tells me 'the prices I gave you are NOT right and you owe $200 more'. He gives me a figure I've not heard before and I say, 'wait a minute, let's go over this'. He got quite prissy and said he was not going over any more numbers, he had made a mistake before, but this was the correct number and if I didn't like it I should just cancel" So . . I did. He promptly hung up.
He has called back two more times begging me to rebook, apologizing for his behavior, whining about how busy he was all day and that made him miscalculate, etc, etc, etc.
So much for any indecision on my part about SeaMiles future use.