Malfunctioning powerbank blew my charger

<p>I bought a powerbank from hyperli used my perfectly working charger to charge the powerbank next thing I knew the light on the powerbank went off thinking it was fully charged I used it to charge my phone but the powerbank was only charged to 52%. So I put the powerbank back on charge. However it wasn't charging. Instead the input from the powerbank was providing power to my charger and I later found out that this caused my charger to blow. I raised this issue with Hyperli and sent them video proof and they are not willing to compensate me to get a replacement international 4 USB charger. I am very disappointed with their service and will never be buying from them again. I urge everyone who reads this also not to purchase any of their products.</p>