Reserve phone wouldnt charge when current phone in for repair

sent remanufactured phone back to refurb co due to problems, thinking I had wiped it? fortunately have a couple of spare Iphone’s so put spare on charge last night just a red band showing this morning on the amount of charge, quickly dug out an even older phone and stuck it on charge with same result after 4 hrs then whilst having lunch there was a ping from both phones and they both started charging

could it be there is a way the refurb shop could have stopped these phones from charging or is there an alternative answer