Hi! Couldn’t find a forum where this fits exactly..

my husband bought me a bracelet from Harrods in T3 on 14/07 when flying back to the US. It doesn’t fit! I am returning to the UK for a few days but flying in to T5. My question is, if I change to American that flys into T3 but connect on to Manchester through T5, will I have access to the T3 shops through flight connections? Harrods have been so vague about everything that I feel like going back to the store where it was actually purchased might be my safest bet!!

thanks in advance!