As described, your reconditioned iPad mini2 has itself developed a hardware fault. In addition, if the iPad has been languishing in a drawer unused and uncharged, the internal battery may also have suffered damage. Unless you have benefit of warranty coverage on this replacement iPad, it is probably beyond viable economic repair.
iPad mini2 now cannot be updated to the current OS version, this being iPadOS 13.5.1. With Apple ending major update support for iPads mini2 and Air1 in September 2019, the last supported version (a recent security patch) is iOS 12.4.7. Some third-party Developers have, for technical reasons, already dropped support for all iOS versions prior to iPadOS/iOS 13 - and whilst still in the minority, you can reasonably expect App support for your iPad mini2 to become more limited over time.
As such, instead of considering repair or a chargeable exchange for another reconditioned iPad mini2, the money might be better spent towards a current model of iPad - all of which will significantly outperform your mini2.
I hope this information and insight is helpful.