Pain in tooth post removal could be due to some infection present before the tooth removal which is gradually settling down or it could be due to some blood clot dislodgement post removal.  please take some painkiller like tab combiflam not more than thrice a day & do some Luke warm water gargles 3-4times a day. even better show it to the dentist who removed your tooth & am sure he will help you out

A piece of tooth left behind can cause pain or else due to dislodged blood clot (Google dry socket).

If the tooth has come out as a whole pain shall subside just visit the dentist he/she will clean the area with saline, if tooth broke while removal some pain is normal but in that case get an xray done to assure no tooth piece is left behind. Regards Dr. Yash

Like any major or minor injury anywhere in the body, extraction socket also takes some time to heal and there can be some pain or discomfort in that area..... the instructions given by your dentist need to be followed meticulously for most comfortable healing phase..... if it is not helping you should first consult the dentist who performed the procedure rather than asking from experts who have not seen the case clinically or even the xrays.....  Regards....