I have never been asked to show my cc on BA flights if I've gone through the secondary cc check system such as Verify by Visa or MasterSecure by Mastercard. If you bought your ticket through a TA, you never have to show your card either.

If you have already purchased your ticket with the lost creditcard, you are protected. So it was totally unnecessary for you to cancel your ticket. The best way to protect yourself is to get a letter from your bank manager stating that you had lost your card number xxxxx and that the new card number xxxx is the replacement. Another way is to perhaps carry a copy of your old card statement which shows your old card number.