the site shows upgrade availability and it doesn't exist

My daughter is flying out to FL (MIA from LHR ) to join us on holiday at the end of Jan. she has booked Econ but has enough miles to upgrade to UC. every day she checks online. on four occasions upgrading to UC has shown up and every time she has rung and been told it is a 'glitch' .
She is prepared to wait until she is at the airport just in case...... but VS are hardly gaining friends with their recurring poor system errors. so frustrating.

When this happens, what does ExpertFlyer show for the fare buckets?

I don't see any G availability for LHR-MIA at all in January. In fact, the first one I see is August!

The only UC reward seat that I can see for Jan is on the 16th.

That wasn't there 2 minutes ago

yeah, Jan 16th has been there for while. she is flying out on Jan 21 and it has appeared four times in the last 3 weeks, but on telephoning she is told it is a mistake. Not , that it has gone, but it should not have been showing anyway. go Figure.

VS 117 0
LHR
01/21/16 9:30 AM
MIA
01/21/16 2:50 PM
333
Daily
87% / 13m J9 C9 D9 I9 Z9 W9 S9 H9 K0 Y9 B9 R9 L9 U9 M9 E9 Q9 X9 V9 N9 O9

VS 5 0
LHR
01/21/16 1:15 PM
MIA
01/21/16 6:05 PM
789
Daily
60% / 21m J9 C9 D9 I9 Z9 W9 S9 H0 K0 Y9 B9 R9 L9 U9 M9 E9 Q9 X9 V9 N9 O9

Both flights that day are apparently wide open in UC.

Yeah - I've had the same thing many times. I imagine VS are sick of hearing about it by now! One can hope that with the new booking system coming later in the year this may not be an issue anymore...

Thanks stuart_f ! there is hope yet ! she has flown UC a couple of times with VS and like us really, really, really likes the LHR CH and the space that UC offers. as a single traveller she prefers not to sit in Econ. So fingers crossed !