Airpod connecting issue

i've had a pair of airpods for around a year now and we recently sent them to be fixed as only one airpod would connect at a time, and i had to hard reset them to get them to both connect. i got them back today and it seems that they have replaced both airpods but not the original case. now the problem is the the little light inside the case is constantly blinking red/amber, even when i press and hold the button on the back of the case. when i try to connect them to any of my devices, only one connects, and the other comes up as a seperate device, and then the music doesn't play out of both. when the airpods are out of the case, the light is green ad i can turn it white to connect but then i encounter the above problem. sorry for specific detail, i'm new to these commnity heplines but i'd be extremely grateful if anyone could offer some support or a solution!