Hhmmm... it's getting curiouser and curiouser
Maybe... if you tried writing or emailing RC about this and get their confirmation (or otherwise) in writing that the formula has not changed. It could be the person on the phone was just being a "job's worth" and not admitting to anything
Maybe... you could try getting it exchanged for something like the Mini Sensible for sensitive tummies. I can let you have a sample if you haven't tried it to see if she/they will deign to give it a go.
and... just maybe... they are all sensing some negative vibes about the stuff now
