welcome to healthcare magic ! the problem that you are facing may be because there was a long gap between the first and the second sitting. If the procedure is not completed within a short time after the tooth gets infected, the infection tends to become chronic. in this case a granuloma
forms around the tooth root which lies in the bone. the granuloma causes pus to build up when the tooth is filled , and the pus keeps getting accumulated again and again. Please take another course of antibiotics, preferrably higher than the first one eg. Ofloxacin
400 mg. I would advise you not to get the cap placed unless the pain subsides completely. please take an X ray
if the pain doesn't subside still. you may need to go for Apicectomy of the root if the filling is proper but there is still infection around the root. Please take a second opinion
of an oral surgeon on the X ray. Take care and all the best!