Frustated about non exchange

I bought pyjamas for my children yesterday, unfortunately it turns out to be small for both of them. But now i cant exchange because apparently they only exchange on level 1 which i fail to understand because level could even only be in november, so must i just keep this small pyjamas throw it away and let my children suffer? Its cold and our kids needs to stay warm, so i fail to understand how PEP makes sense of all this...its very frustrating and confusing...