Having now surfaced from a bout of 'flu, my thanks for all comments received.

To answer Smirnoff, it was my mistake: the actual figure was 18 days then, and as of today the availability for 2 reward Club seats on the separate legs LHR- GRU and GRU to EZE are 15 and 18 days respectively in Nov 07.

As for G-BOAC's rebuke of 29 Dec, the tone of my post may have been unfairly harsh, but it reflects the accumulated frustration I have following a series of poor experiences with BA over the past 15 months. Regrettably the Exec Club call centre manager was clearly exasperated with my probing for an explanation, and treated me as a nuisance.

And to answer Paulb, they would definately not allow the use of the voucher for LHR-EZE when they have to check availability on two separate sectors rather than a through flight . This is probably reflected in Neilsdc's observation that stopovers are not offered on LHR-EZE.

Clearly this is not a straightforward route, and I consider my self lucky to have now booked outbound only as far as GRU (from where we shall start our holiday) , though I do have seats for a return EZE-LHR.

Happy New Year..!