unable to return during lockdown - Consumer Complaint for PEP STORES

On the 02.05.2020, we went to pep store in Ennerdale Metropolitan center to buy some clothes for the children for winter because of the lockdown we could not take the kids with to try on the shoes for the correct size, so we purchased a size to big for my niece and within a few minutes went back to the shop to change the shoe for a smaller size and we were told that we cannot change the shoe as they do not have the mandates to do so because of the lockdown, so this does not make sense that we are allowed to buy essentials for the children, and they cannot be with us when doing so to fit on stuff then what are we suppose to do if the shoes and clothing does fit?