I face the same problem ,and I tried more than 50 times ,but after clicking on payment it redirects to login page evertime ,i tried via every payment options given but no solution. This may happen because first time when try to make payment it open and I filled the upi half and cancel it due to some personal issue so I make no payment and no amount deducted from my account .after that the problem started ,.
Please help me .
I also complained on aiims Gmail site but didn't get any response.
Centre are filling fastely.